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H L Jenssen

Publications and source records attributed to H L Jenssen.

At least 19 recordsLinked to original sources
PubMed1990

[Effect of pulsating electromagnetic field therapy on cell volume and phagocytosis activity in multiple sclerosis and migraine].

PEMF treatment was studied in 10 patients with multiple sclerosis and 10 patients with migraine. In both patients' groups a single treatment induced a significant rise of yeast particle uptake by blood granulocytes. The percentage of phagocytizing cells was increased in migraine patients only. In both patients' groups 20 PEMF treatments caused a reduction of particle uptake, whereas the percentage of phagocytizing cells remained unchanged. In migraine patients the opsonic capacity of serum and the mean cell volume of erythrocytes, lymphocytes and granulocytes were initially reduced, but increased during the course of 20 PEMF treatments. The biphasic changes of cell volume and phagocytic activity are interpreted as a result of counter-regulation of the organism in response to the primary PEMF effect.

Electromagnetic Fields↗
PubMed1989

[Phagocytic reactivity of granulocytes in the peripheral blood of patients with multiple sclerosis and normal probands].

For estimation of phagocytic activity the uptake by granulocytes of heat-inactivated, opsonised yeast particles (Saccharomyces cerevisiae) was measured. Peripheral granulocytes of multiple sclerosis patients revealed an enhanced ability for phagocytosis in comparison to normal healthy controls, if tested with normal serum as opsonic source. An activated state of cells in multiple sclerosis is supposed. The selective influence on granulocyte phagocytosis of treatment by ultraviolet-irradiated blood in multiple sclerosis patients supports the view of altered reactivity of these cells in comparison to normal controls.

Antigen-Antibody Complex↗
PubMed1988

The binding of IgG1 containing immune complexes to the FcR of allogenically activated T cells induces changes in the membrane potential and the cell surface charge.

The effect on membrane potential and cell surface charge of binding immune complexes containing IgG1 and IgG2a monoclonal antibodies to Fc receptors was studied in resting and allogenically activated murine T cells. IgG1 complexed by antigen or heat aggregation induced electrophysiological changes on activated T cells. A biphasic alteration of membrane potential was detected by measurement of the intra- and extracellular distribution of the fluorescent dye, DiOC6. A short-lived hyperpolarization, detectable for 4-6 min after adding the respective ligand, was followed by a longer lasting depolarization. The cell surface charge, measured by cell electrophoresis, was also changed. This alteration was detected 2-4 hr after addition of immune complexes and disappeared by the 8th hr of incubation. Monoclonal antibody 2.4.G2, reactive with mouse FcR, induced a similar membrane potential response on activated T cells, but did not affect the cell surface charge. Monomeric IgGs and complexes of IgG2a did not modify these parameters. FcR ligands had no effect on the studied characteristics of resting T cells.

Animals↗
PubMed1988

[Effect of ultraviolet irradiation of autologous blood on cell volumes, cell adhesion and phagocytosis in normal probands and patients with multiple sclerosis].

UVB induced changes of blood cell properties were investigated in 12 MS patients and in 10 healthy volunteers serving as normal controls. The mean cell volume (MCV) was determined by electronic sizing, the granulocyte and lymphocyte adherence was estimated in a capillary assay, and the phagocytic activity of granulocytes was measured in a test system based on the incorporation of opsonized baker's yeast (Saccharomyces cerevisiae). In MS patients the MCV of red cells and lymphocytes decreased rapidly within 6 UVB treatments. In contrast, the reduction of the granulocyte volume was delayed (between the 6th and 12th UVB). In the control group the mean value of the red cell and lymphocyte MCV remained rather unaffected. There was a slight rise of the granulocyte volume after the 6th UVB. The only significant change of adherence was an increase of granulocyte adherence in MS patients. Untreated patients had a significantly enhanced phagocytic activity in comparison to the control group. 6 UVB treatments included a significant reduction of the phagocytic activity in MS patients. However, subsequently the percentage of phagocytizing cells increased again, whereas the particle uptake per cell continued to decrease. In the control group only minor UVB induced changes of phagocytosis were observed. The in vitro UV irradiation caused an enhanced phagocytosis in the majority of cases in both controls and MS patients. In general, under the UVB treatment all parameters examined changed in the sense of a normalisation, in that the measured values reached a new level lying between the extreme pretreatment values accompanied by a reduced standard deviation. The effect of UVB was more pronounced in MS patients when compared with normal controls. This could result from an enhanced sensitivity to the influence of UVB of pathologically altered cells in MS patients. The monitoring of the MCV of red cells and lymphocytes as well as the repeated testing of granulocyte phagocytosis are recommended for supportion of therapy planning and follow-up of MS patients.

Blood↗
PubMed1988

[The binding behavior and functional significance of Fc receptors for IgG on T lymphocytes of the mouse].

In consequence of allogenic stimulation of mouse spleen lymphocytes the binding of fluorescein isothiocyanate conjugated aggregated IgG (FITC-aggr. IgG) per cell is increased (higher affinity of receptors and/or higher number of receptors). A higher specificity of the FITC-aggr. IgG binding to allogeneically stimulated lymphocytes in comparison to fresh prepared resting and syngeneically cultivated lymphocytes could be only detected on the higher fluorescing allogeneically stimulated cells. Increased amount of Fc-receptors for IgG (Fc gamma R) is mainly found on T-lymphocytes with the Lyt-1 + 2 +-phenotype. The manipulation of that Fc gamma R on T-lymphocytes, which were expressed in consequence of allogeneic stimulation by binding of respective ligands, did not change the original effect of nonmanipulated, allogeneically activated cells on a primary MLR. But if the cells were negatively selected by means of monoclonal antibodies and complement, the originally suppressive effect of allogeneically stimulated Lyt-2 positive cells on a primary MLR was abolished by manipulating the respective Fc gamma R.

Animals↗
PubMed1987

[Relations between concanavalin A binding and cell proliferation. Comparison of Lyt-1+ and Lyt-2+ lymphocyte subpopulations from the spleen of unstimulated mice and mixed lymphocyte culture].

Fluorescein isothiocyanate conjugated concanavalin A (FITC-Con A) binding to negatively selected Lyt-1+ and Lyt-2+ spleen cells from nonstimulated mice and from mixed lymphocyte culture (MLC) was tested in parallel with the effect of Con A on proliferation of these cell subpopulations. Lyt-2+ spleen cells from nonstimulated mice bound more FITC-Con A but proliferated in response to Con A to lesser extent than Lyt-1+ cells. allogeneically stimulated Lyt-1+ cells were inhibited by Con A and bound FITC-Con A in higher amounts and more specifically than Lyt-2+ cells. In syngeneic control culture, no remarkable differences in both Con A binding and Con A-induced proliferation of the lymphocyte subpopulations were found. The results are discussed in context of Lyt-phenotypic and functional differences between T cell subpopulations and seem to contradict a strict correlation between Con A binding and cell function.

Animals↗
PubMed1986

Flow cytometric estimation of transmembrane potential of macrophages--a comparison with microelectrode measurements.

Potential-dependent accumulation of the lipophilic cationic dye 3,3' dihexyloxacarbocyanine (DiOC6(3)) in macrophages has been investigated. Resulting fluorescence of cells was measured by flow cytometry. Alterations of membrane potential of macrophages were induced by ionophore treatment (valinomycin and gramicidin) in a dose-dependent (10(-5) M-10(-7) M) and time-dependent (0 min-45 min) manner. Resulting changes in relative fluorescence intensity were compared with changes of transmembrane potential measured by intracellular recordings obtained by applying glass microelectrodes. The comparative studies offer the possibility to calibrate the flow cytometric estimate of membrane potential of suspended cells. Equilibration of dye partition between cells and surrounding medium is strictly potential-dependent at dye concentrations between 5 X 10(-8) M and 10(-7) M and within an incubation interval from 10 min up to 30 min after addition of dye. Conclusions are drawn concerning the field of application of the optical method. Dynamics of electrical processes following ionophore treatment are discussed in terms of molecular mechanisms of altered ionic transport.

Animals↗
PubMed1985

[Heterogenous immune reactivity in brain tumors: results of cellular immunity in relation to brain tissue antigens].

In brain tumors and other neurological diseases cell-mediated immune reactions to fetal brain tissue antigens (FBA), normal tissue antigen of adult brain (NTA) and tumor-associated antigens of different brain tumors (TAA) have been analysed. The detection of sensitized lymphocytes using the MEM-(macrophage-electrophoretic-mobility-) test revealed general tumor-related results applying the FBA, in some extent a cross reactivity and partly no kind of reaction. A phase-specific reactivity to normal brain antigens could not be found, only cases of multiple sclerosis produced restrictive results employing the NTA. By testing tumor-associated brain antigens different reaction types were seen: The common TAA caused a tumor-characteristic reaction; the histo-specific TAA predominantly presented a organotypic form of reaction, confined a histo-specific reaction pattern; in some cases there were found inadequate, non-corresponding reactions as well as unreactivity. With regard to different types of reaction the problems of heterogeneity of the brain tumors and the cellular immune response--i.e. a heterogeneity of 1. or 2. order--were discussed including further factors concerning several special conditions in the nervous system.

Antigens, Neoplasm↗
PubMed1985

Effect of islet cell surface antibodies on neonatal rat pancreatic islet cells or isolated islets of Langerhans in vitro.

Islet cell surface antibodies (ICSA) raised by immunizing rabbits with pancreatic islet cell suspensions were characterized with respect to some aspects of their influence on neonatal rat islet cells or isolated islets of Langerhans. The removal of unspecific cytotoxic factors by absorption with liver powder and spleen cells was reflected in changes of the antibody binding pattern to islet cells demonstrated by flow-cytometric analysis as well as the corresponding 51Cr-release from prelabelled islet cells. Using neonatal rat pancreatic islets as a target, fresh ICSA-positive serum provokes a beta-cell specific insulin leakage in a concentration dependent manner. In contrast to heat-inactivated antiserum the complement-mediated cytotoxic effect of rabbit anti-rat islet cell surface antiserum seems to have its morphological expression also in alterations of the islet surface structure as revealed by scanning electron microscopy.

Animals↗
PubMed1984

Flow cytometric measurements of phagocytosis. I. A methodical and comparative study.

A flow cytometric technique is described for measurement of phagocytic activity in human leucocytes using FITC-labelled latex particles (0.77 micron). Cell suspensions separated from peripheral blood by dextran sedimentation were hemolyzed to avoid particle uptake by erythrocytes. The leucocytes were incubated for various time intervals with a standardized solution of 2 x 10(7) FITC-labelled latex particles per 2 x 10(5) leucocytes in 0.6 ml medium. Relative fluorescence per cell was measured on the basis of 10(5) cells, and a simple technique has been described to evaluate data characteristic for different steps of phagocytosis and to discriminate between phagocytizing and non-phagocytizing cells. In comparison, rice starch phagocytosis has been measured microscopically. A positive correlation between both methods has been found in 11 patients with different disease-related phagocytic capacity.

Erythrocytes↗
PubMed1984

Immunological reactivity of tumor associated glycoproteins prepared by affinity chromatography.

Crude 3M KCl extracts prepared from tumor tissue and ascitic tumor cells of methylnitrosourea-induced fibrosarcoma of CBA mice or of a human stomach adenocarcinoma were gelfiltrated on Ultrogel AcA 34. Single fractions of these preparations were incubated with spleen cells of tumor bearing mice or blood peripheral lymphocytes. The response was detected by MEM-technique. Antigenic activities were found in molecular weight ranges from 200 to 300 kD (P1) and from 40 to 70 kD (P2). Single glycoproteins of the P1- and P2-fractions could be separated by affinity chromatography on immobilized D-galactose specific mistletoe lectin I, as detected by electrophoresis on microgradient gels (1.2-40%) or on SDS polyacrylamide slab gels. Especially the isolated glycoproteins of the P1-fractions are responsible for the observed antigenic reactivity, assayed in vitro by the MEM-technique and in vivo by foot pad swelling test.

Adenocarcinoma↗
PubMed1983

The use of protein beads as immunoadsorbent for the column fractionation of lymphocytes.

Beads of calf serum proteins (CSB) with antigen-antibody complexes or antigen by activation with glutaraldehyde were used as immunoadsorbents for the fractionation of mouse lymphocytes. T-lymphocytes could be separated by this method with high purity. The precursors of antibody-forming cells were completely eliminated from spleen and bone marrow cell suspensions. The unspecific binding of lymphocytes to CBS or Sepharose was similar and not selective for T or B lymphocytes.

Animals↗
PubMed1982

[Methods of isolating immune cells--critical assessment, artifacts].

This paper describes common used methods of immune cell separation such as separation by density-gradient, cell electrophoresis, cell adherence, affinity chromatography, isolation of cell populations by antisera and complement, by cell sorting, by monolayer and lectins. The authors give a critical evaluation in respect of yield and purity in relation to the extent of the experimental procedure and regard eventual artefacts.

Animals↗
PubMed1982

Flow-cytometric analysis of glucose induced changes of the transmembrane potential and optical density in pancreatic islet cell suspensions.

Glucose-induced insulin release of beta cells of pancreatic islets is associated with islet cell membrane electrical activity. We measured the membrane potentials of neonatal rat islet cell suspensions by means of "optical probes" by flow cytometry. Moreover, we determined the narrow angle light scattering and light absorption in direction of the laser beam, respectively. In both these cases two or three clusters of the whole cell population showing different responses to glucose could be distinguished. Glucose-dependent depolarization as well as loss in optical density of cells of pancreatic islets should be associated with the physiological function of insulin producing beta-cells. It is concluded that changes of the membrane potential and/or optical density of islet cells produced by insulin secretagogues can be analysed by flow cytometry which might provide the basis for sorter experiments to separate specific subpopulations of cells of pancreatic islets.

Absorption↗