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Biomedical subjects

M Ernst

Publications and source records attributed to M Ernst.

At least 253 records · Page 14Linked to original sources
PubMed1986

Suppression of Staphylococcus aureus Cowan I-induced immunoglobulin synthesis in vitro: discrimination between the presence of suppressor T cell precursors and effectors.

In co-cultures with control cells lymphocytes obtained from some patients with hypogammaglobulinaemia can suppress PWM but not S. aureus Cowan I-induced polyclonal immunoglobulin production. When such co-cultures were stimulated at the same time with both mitogens, the response was greatly suppressed. This phenomenon was further studied in cultures of lymphocyte populations isolated from healthy donors. It was found that suppressor T lymphocytes activated by PWM in cultures co-stimulated with Con A, with high T:B cell ratio, or with an increased proportion of OKT8+ T cells can suppress the S. aureus-induced response. In contrast, under the same conditions S. aureus did not activate suppressor cells. Moreover, in cultures stimulated with this polyclonal B-cell activator OKT8+ lymphocytes could serve as helper cells.

Agammaglobulinemia↗
PubMed1986

A phase I/II trial of recombinant interleukin-2 in AIDS/ARC: alterations of phenotypes of peripheral blood mononuclear cells.

In the context of a clinical phase I/II trial with recombinant interleukin 2 (rIL-2) surface phenotypes of peripheral blood leukocytes and delayed-type hypersensitivity skin reactions were monitored in four patients with acquired immunodeficiency syndrome (AIDS) and three patients with AIDS-related complex (ARC). The phenotypic alterations during the 14-day course of treatment were characterized by 1. a decrease in the proportion of OKT9 positive lymphocytes in AIDS patients, 2. an increase in the proportion of Leu8-/Leu3a+ lymphocytes in all patients and, in particular, 3. the transient significant decrease of the Leu7+/OKT3+ ratio, which was elevated pretherapeutically in AIDS patients (0.78 +/- 0.21) and ARC patients (0.48 +/- 0.06) compared to healthy controls (0.18 +/- 0.08). In contrast, the T4/T8 ratio of the patients' T-cells was not significantly affected by rIL-2 treatment. Delayed skin reactivity to recall antigens was improved in some patients. In one patient the surface phenotypes of peripheral blood mononuclear cells were determined on the first day of rIL-2 treatment in the morning before and in the evening after infusion of rIL-2. A rise of HLA-DR positive non-B-lymphocytes was observed. We conclude that the Leu7/OKT3 ratio, OKT9 and HLA-DR may be useful markers for monitoring the effects of biological response modifiers in patients with AIDS/ARC.

AIDS-Related Complex↗
PubMed1986

[Current aspects of evaluating wood dust-induced adenocarcinomas of the nose and paranasal sinuses].

The evaluation of 40 patients with adenocarcinoma of the nasal cavity shows that these patients had been exposed to oak and beech dusts proving the causal connection between this type of wood dust and adenocarcinoma of the nose. In view of this knowledge, compensation in accordance with section 551 (2) RVO (Reichsversicherungsordnung: social insurance statute) can be recommended in individual cases after intensive occupational exposure to oak or beech dust over many years.

Adenocarcinoma↗
PubMed1985

The effect of surgery and anesthetic agents on granulocyte-chemiluminescence in whole blood.

The effect of anesthesia and major abdominal surgery on zymosan-induced chemiluminescence (CL) of neutrophil granulocytes was evaluated. CL was measured in diluted whole blood taken at distinct intervals within the perioperative period. In addition, blood samples from healthy volunteers were supplemented with ether and halothane to investigate the in vitro effect of these agents. The phagocytosis-induced CL was not found to be depressed by anesthesia and surgery. Only at supranarcotic concentrations was CL reduced. Surgery and anesthesia, therefore, do not appear to impair this defense system significantly under the conditions of this investigation.

Abdomen↗
PubMed1985

Response of human T lymphocytes to phytohemagglutinin (PHA) after sequential depletion of monocytes, HLA-DR+, Leu11a+, and Leu7+ cells.

The experiments presented in this paper deal with the question of whether there is an absolute requirement for alpha-naphtylacetate esterase (ANAE)-positive monocytes, HLA-DR+, Leu11a+, and/or Leu7+ cells to stimulate human peripheral blood T lymphocytes by phytohemagglutinin (PHA). Purified (p) T lymphocytes containing less than 0.1% ANAE-positive monocytes were isolated from human peripheral blood mononuclear cells (MNC) by sequential removal of carbonyl-iron phagocytic cells and of low-density cells by density gradient centrifugation and isolation of E-rosette-forming cells (E-RFC). These pT-cells were further depleted of HLA-DR+, Leu11a+, and/or Leu7+ cells using monoclonal antibodies and cell sorting. The T lymphocytes were stimulated by PHA in an ultra-micro culture in glass capillaries at a volume of 1 microliter or 2 microliters, containing 1000 cells per culture. With this method, the accessory cell requirement could be studied under limiting cell number conditions. The results show that pT-cells can be stimulated by PHA in the absence of ANAE-positive monocytes. No ANAE-positive monocytes were found in the culture after stimulation, indicating the lack of differentiation into ANAE-positive monocytes from ANAE-negative precursors. A rabbit antiserum against leukocytic pyrogen (LP, also containing anti-IL 1 activity) only reduced but did not abrogate the stimulation of pT-lymphocytes by PHA. Addition of adherent cells resulted in an enhancement or in an inhibition of the response of pT-lymphocytes to PHA, depending on cell concentration and culture time: The lower the number of cultured T lymphocytes and the shorter the culture time, the higher was the enhancing activity by additional adherent cells, and vice versa. Further purification of the pT-cells using monoclonal antibodies and cell sorting led to the finding that depletion of either HLA-DR+, Leu11a+, or Leu7+ from pT-cells only reduced but did not abrogate the stimulation of the pT-cells by PHA. However, in absence of HLA-DR+ and Leu7+ cells, the pT-lymphocytes totally failed to respond to PHA. This abrogation of the response was not observed when pT-cells were depleted of HLA-DR+ and Leu11a+ cells. In addition, T11+/HLA-DR- T lymphocytes isolated from E-RFC by positive selection in a cell sorter also responded to PHA.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal↗
PubMed1985

The analgesic effects of aspirin and placebo on experimentally induced tooth pulp pain.

We examined the relative analgesic potency of aspirin and placebo in a within-subject-repeated-measure experiment using a precision tooth pulp stimulation technique with long-term stability (r = 0.93) for more than two months between measures. The attenuation of pain perception was evaluated using a standardized magnitude estimation procedure and constructing an individual psychophysical function for each trial. The data were fit equally well by either a straight line (Y = mX + b) or a power function (Y = mXa + b). Using the line fit and distribution insensitive conservative statistical tests, the effect of each treatment was compared to baseline and the treatments were compared to each other. In randomized, double-blind trials we found reliable effects of both aspirin (p less than 0.001) and placebo (p less than 0.001) but no difference (p = 0.08) between these two treatments. However, on an individual basis, 12 of 17 subjects displayed a larger analgesic response to aspirin than to placebo (p less than 0.05).

Adolescent↗
PubMed1984

Dissociation of responses measured by natural cytotoxicity and chemiluminescence.

Monocyte/macrophage-mediated cytotoxicity requires the generation of activated oxygen radicals, which can be measured by chemiluminescence (CL). To investigate whether natural killer (NK) cell activity required activated oxygen species, both cytotoxicity against K562 target cells and CL were measured in cell populations of human peripheral blood. The following results were obtained: (a) Peripheral blood mononuclear cells (MNC) showed NK activity and a response in CL, which could be induced by viable or paraformaldehyde-fixed K562 target cells as well as by latex particles. (b) Both T cells and non-T cells exhibited NK activity, but T cells gave no K562- or latex-induced CL responses. (c) Depletion of phagocytic cells from MNC abolished CL, but only marginally affected NK activity. (d) Reconstitution of phagocyte-depleted MNC with adherent cells revealed a superadditive enhanced CL response, but had no augmenting effect on NK activity. (e) Phagocyte-depleted cell populations, enriched for NK activity by density gradient centrifugation, did not respond in K562- and latex-induced CL. (f) MNC, highly enriched for NK activity by cell sorting with a cytofluorograf using the fluorescein isothiocyanate-labeled monoclonal antibody anti-Leu-11a, responded only with reduced CL, whereas the NK activity was enriched up to 45-fold. From these results it is concluded that NK cell-mediated cytolysis of K562 target cells and K562-induced CL are not functionally correlated, but represent properties of two distinct cell populations, namely NK cells and monocytes.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1984

Isolation and subfractionation of human peripheral blood mononuclear cells (PBMC) by density gradient centrifugation on Percoll.

The use of Percoll for isolation and subfractionation of PBMC and T-lymphocytes by discontinuous and continuous density gradient centrifugation is described: PBMC were isolated from human peripheral blood by discontinuous density gradient centrifugation on Percoll. The use of Percoll instead of Ficoll-Isopaque has the advantage that Percoll, in contrast to Ficoll-Isopaque, does not alter the density of monocytes. Therefore, a better separation of lymphocytes and monocytes was achieved after subsequent continuous density gradient centrifugation on Percoll. E-RFC were isolated by discontinuous density gradient centrifugation after a first low speed centrifugation step banding lymphocytes and SRBC on a Percoll-Ficoll cushion, and a subsequent high speed centrifugation step separating high density rosettes and SRBC from low density non-E-RFC. The advantage of this procedure is the short time of performance and that there is no need to resuspend the lymphocyte/SRBC pellet. PBMC, nph.PBMC T-lymphocytes were further subfractionated by continuous density gradient centrifugation on Percoll. The method described here resulted in a good separation of lymphocytes and monocytes. However, to obtain lymphocyte fractions with minute numbers of contaminating monocytes, a depletion of monocytes prior to further subfractionation of the lymphocytes by continuous density gradient centrifugation is recommended. A marker analysis of T-lymphocytes subfractionated by continuous density gradient centrifugation on Percoll shows that high density T-lymphocytes are enriched in ANAE positive lymphocytes of type 1 and depleted of ANAE positive lymphocytes of type 2. Low density T-lymphocytes are enriched in ANAE type 2 cells and depleted of ANAE type 1 cells. On the other hand, no considerable differences were found when analyzing the T-cells from different fractions for differentiation antigens by means of monoclonal antibodies (anti Lyt 3, OKT4, and OKT8). The results may indicate that subfractionation of T-lymphocytes by continuous density gradient centrifugation on Percoll provided T-cells in different functional states rather than T-cells of distinct subclasses.

Antibodies, Monoclonal↗
PubMed1984

Monoclonal antibodies against immunoglobulin classes as standardizable reagent in B-cell lymphoma and leukemia diagnosis.

From several fusions of mouse myeloma cells X63-Ag8.653 or NS 1 with spleen cells from BALB/c mice immunized with purified IgG or IgM, we produced a series of monoclonal antibodies directed against IgA, IgM and IgG. The specificity of the antibodies was proved in an enzyme linked immunosorbent assay (ELISA) with purified IgA, IgM and IgG respectively. For diagnostic use we tested our antibodies in paraffin, and cryosections, in blood smears and in cytocentrifugates of peripheral blood. As a test system we used the immunoperoxidase staining method. We showed that the corresponding antigenic determinants are resistant to all used methods of material fixation, and that the monoclonals react with the specific antigen in material of normal donors as well as in pathological material.

Animals↗
PubMed1984

[The C3 activating capacity in human serum--measured as monocyte mediated chemiluminescence].

Phagocytosing monocytes form activated oxygen species which can be detected by the luminol-mediated chemiluminescence (CL). C3b-coated particles yield enhanced CL-signals due to their binding to the monocytes' C3b-receptor. Thus, the zymosan-induced monocyte-CL in a medium containing fresh or heat-inactivated serum provides a means of measuring in sera the capacity to activate C3.

Biological Assay↗
PubMed1983

Initial appearance of myomesin in differentiating muscle cells.

The time between the appearance of the striated-muscle-specific M-line protein myomesin and the previous mitosis was measured in individual chick breast muscle cells. The shortest time interval (16 h) was measured with time-lapse cinematography followed by indirect immunofluorescence on 84 cells during the first two days of culture. During these experiments diffuse, cell border and cross-striated fluorescent patterns were observed in both bipolar and non-bipolar cells. A quantitative comparison of the spatial distribution of myomesin to cell morphology and time of culture revealed considerable variation among individual cells. These results indicate that the mechanisms regulating these factors during terminal differentiation are separable and not strictly coordinated.

Animals↗
PubMed1983

The early effect of sublethal X-irradiation of phagocytic cells in mouse blood and the influence of cystamine as measured by chemiluminescence.

The metabolic burst accompanying phagocytosis of granulocytes (PMN) leads to the generation of activated oxygen species such as O-2, H2O2, 1O2 and OH; which give rise to chemiluminescence (CL) in the presence of luminol. Reliable CL-measurements of stimulated PMN can be carried out in freshly drawn mouse blood, when photon counts are related to the number of PMN. Effects of low dose total body X-irradiation were studied using C57B1/6 mice. It was found that 24 and 48 hours after irradiation (0.24-0.95 Gy) CL of whole blood was slightly decreased. If however CL-counts were related to the number of PMN, an enhanced CL per single granulocyte was recorded. The administration of cystamine leads to an immune stimulating effect of unirradiated animals. In animals, who received 0.95 Gy a distinct radioprotective effect of cystamine can be observed.

Adenosine Diphosphate↗
PubMed1983

Zymosan-induced chemiluminescence of granulocytes in incubated human whole blood. The role of platelets.

Zymosan-induced chemiluminescence (ZI-CL) of whole blood which is mainly the response of granulocytes can be used as a rapid, simple and reliable diagnostic tool for hematological and allergic disorders. ZI-CL of whole blood remained unchanged when stored at 0 degree C for 4 hr, whereas it increased by incubation at 37 degrees C. This phenomenon points to platelet-granulocyte interaction during the incubation. ZI-CL of freshly prepared suspension of leukocytes and erythrocytes was enhanced by adding platelet rich plasma (PRP) obtained from incubated blood. Enhanced CL response was observed when erythrocytes or factors derived there of were present in incubated blood. Platelet stimulating factor (PSF) was prepared from incubated erythrocyte suspension. This factor also increased ZI-CL of granulocytes when incubated with fresh PRP. The consistent inhibition of CL of incubated blood by apyrase (0.5 U/ml) and the increased response of fresh blood by the addition of ADP (10(-5) M) suggested that this factor might be ADP itself. Platelets stimulated by this factor may respond more markedly to added zymosan for still unexplored reason with enhanced CL.

Adenosine Diphosphate↗
PubMed1983

Chemiluminescence of granulocytes and monocytes in diluted whole blood samples: a tumor marker?

Granulocytes and monocytes can attack malignant cells by activated oxygen species. They thereby emit photons which may be measured as chemiluminescence (CL). The zymosan-induced and luminol-amplified CL response of granulocytes and monocytes was measured in diluted whole blood samples of healthy volunteers and patients with benign and malignant disease. In tumor patients the CL activity was significantly stimulated. Following tumor reduction by radical or palliative operations, the CL values decreased to normal within weeks, whereas no response was seen after exploratory laparotomy without tumor reduction. Operations for benign disease did not influence the CL activity. The results suggest that the stimulation of CL activity in tumor patients is reversible. CL measurements in whole blood samples may play a future role as a nonspecific tumor marker.

Granulocytes↗
PubMed1983

Chemiluminescence measurements of immune cells--a tool in immunobiology and clinical research.

Since the initial observation of chemiluminescence associated with metabolic stimulation of polymorphonuclear leukocytes a multitude of studies have confirmed that chemiluminescence is a) dependent on the generation of activated oxygen species and b) intimately correlated to the paramount function of granulocytes: to kill bacteria and to cause tissue damage at sites of chronic inflammation. Chemiluminescence is not exclusively generated by polymorphonuclear leukocytes and certainly not only generated by phagocytic stimuli. Besides phagocytic stimuli, surface active reagents (e.g. phorbol myristate acetate), lectins, antigen-antibody complexes, complement components, and some lymphokines are able to evoke chemiluminescence responses in polymorphonuclear leukocytes, monocytes, and macrophages. In this contribution we present evidence for a dependence of macrophage chemiluminescence during phagocytosis on the calcium binding protein calmodulin. In a second example of macrophage chemiluminescence we demonstrate that macrophage chemiluminescence is a good tool for testing the mediator function of a lymphokine, namely macrophage cytotoxicity factor. In a clinical application we determined the zymosan-induced and luminol-amplified chemiluminescence in diluted whole blood samples from healthy volunteers to establish the normal range of chemiluminescence activity of phagocytic cells. A significant day time variability of the chemiluminescence activity was observed in 6 volunteers. Therefore, blood sampling for the chemiluminescence measurements was standardized. Compared with the control group the specific chemiluminescence activity (activity related to 10(3) phagocytic cells) was significantly increased in both 1) patients with acute inflammatory disease and 2) in patients with carcinoma. The specific chemiluminescence activity of the two groups of patients did not differ.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Measurement of chemiluminescence in freshly drawn human blood. II. Clinical application of zymosan-induced chemiluminescence.

The aim of the present study was to investigate chemiluminescence (CL) of stimulated peripheral phagocytic cells (PC, i.e. granulocytes and monocytes) in patients with malignant disease at various stages. As a first step the zymosan-induced and luminol-amplified CL was determined in diluted whole blood samples from healthy volunteers. A characteristic daytime dependence of the CL activity was observed in six volunteers which had to be taken into account for blood sampling. The detectable CL was demonstrated to depend on the number of erythrocytes in the assay, but correction for this is not necessary for clinical investigation. The specific CL activity (activity related to 10(3) PC, was significantly but identically increased both in 1) patients with acute inflammatory disease and 2) in patients with carcinoma. The total CL activity (activity/microliter whole blood), however, was significantly increased in patients with acute inflammation as compared to the tumour group. This greatly reflects the leucocytosis of patients with acute inflammation. In a small number of patients with benign and malignant disease the CL of PC was measured both pre- and postoperatively. Operations in benign disease and palliative operations in malignancy did not influence the CL activity. In contrast, CL activity returned to normal after clinical cure by radical tumour resection.

Blood↗
PubMed1982

T-lymphocytes in experimental autoimmune myasthenia gravis. Isolation of T-helper cell lines.

The role of T-lymphocytes in Experimental Autoimmune Myasthenia Gravis (EAMG) was investigated. We generated highly purified, acetylcholine receptor (AChR)-specific T-cell populations and subsequently characterized these cell lines with respect to their membrane phenotype and their function. Using a series of mouse monoclonal antibodies directed against rat lymphocyte surface differentiation antigens, the vast majority of line cells was shown to express a leucocyte common antigen, a T-common antigen and a T-helper antigen. Small subpopulations were Ia or T suppressor antigen-positive. Adaptive transfer to sublethally irradiated, thymectomized recipients revealed that 1 X 10(6) AChR-specific line cells could cooperate effectively with 10 X 10(6) AChR-primed, complement (C3) receptor-bearing (B-cell enriched) spleen cells in the production of anti-AChR autoantibodies. Recipients of B-cells along with relevant line cells developed an acute myasthenic syndrome 6-7 days after cell transfer. Electron-microscopical examination revealed the typical features of "acute phase" EAMG with heavy mononuclear infiltration. There was, however, no evidence antibody-independent cytotoxic activity exerted by AChR-specific line cells.

Animals↗