Search PubMed⌕ Search

Biomedical subjects

N Fuchsberger

Publications and source records attributed to N Fuchsberger.

At least 37 records · Page 2Linked to original sources
PubMed1993

In vitro antiproliferative effect of interferon alpha in solid tumors: a potential predictive test.

An in vitro test for the antiproliferative effect of human leukocyte interferon (IFN-alpha) was performed in primary cultures of tumor cells obtained from 32 patients with either malignant melanoma (13), renal carcinoma (4) or bladder carcinoma (15). Our results demonstrated activity of IFN in all three groups of solid tumors. However, appreciable differences in sensitivity to antiproliferative effect of IFN between individual tumors of the same type were found. The potential of this antiproliferative test for prediction of treatment response in IFN-therapy is discussed.

Adult↗
PubMed1992

Synthesis of 23 K acute-phase protein by HBV genome carrying PLC/PRF/5 human hepatoma cells.

Elevated synthesis of 23 K protein by human hepatoma PLC/PRF/5 cells was observed after their treatment with conditioned medium from concanavalin A stimulated peripheral-blood monocytes. Increased amount of this protein was first determined 4 hr after the treatment and its maximal level was reached 48 hr later. The role of the 23 K protein remains so far unknown.

Acute-Phase Proteins↗
PubMed1991

Interferon alpha-induced modulation of leukocyte cell surface antigens: immunocytofluorometric study with human leukaemia/lymphoma cell lines.

Recombinant interferon alpha enhanced the MHC class I antigen density on human leukaemia/lymphoma cell lines REH, U-937 and HL-60, as measured by immunocytofluorometry using specific monoclonal antibodies. A similar effect was induced (as demonstrated in REH cells), also by human leukocyte interferon-alpha. The latter, however, caused no major alterations in the expression of leukocyte common antigen (ICA; CD45) and transferrin receptor (CD71) in the cell lines examined. In REH cells, there was no interferon-induced alteration of CD10 antigen (CALLA), which in this cell line is markedly down-regulated by 12-0-tetradecanoyl-phorbol-13-acetate (TPA). A decrease of CD4 antigen density on the cell membrane was induced by interferon-alpha in monoblastoid U-937 cells. No induction of MHC class I and II antigens by interferon-alpha was found in K-562 cell subline.

Antigens, CD↗
PubMed1990

Relationship between depression of HBsAg production and DNA synthesis by interferons in human hepatoma cell line.

The influence of different interferons (IFNs) on HBsAg production and DNA synthesis was studied in PLC/PRF/5 cells using 30 I.U./ml of natural HuIFN-alpha, 25 I.U./ml of recombinant HuIFN-alpha 2, and 5 I.U./ml of natural murine IFN-alpha/beta. All three IFN types inhibited significant inhibitory effect on HBsAg production during the second 24 hr-interval following their addition. After 96 hr HBsAg production had returned to normal levels. Natural HuIFN-alpha clearly depressed cellular DNA synthesis 24 hr after IFN addition which returned to normal within the next 24 hr. Recombinant HuIFN-alpha 2 influenced DNA synthesis only slightly and the mouse IFN-alpha/beta showed no effect.

Carcinoma, Hepatocellular↗
PubMed1988

Human interferon alfa therapy and hepatitis B virus markers in the serum of patients with chronic course of illness.

Dynamics of serum levels of HBsAg, HBeAg and anti HBc were followed during human interferon alpha (Hu IFN alpha) therapy of patients with chronic active or chronic persistent hepatitis B. More or less expressed oscillations of HBsAg serum levels seen in two out of our six treated patients seemed to occur due to IFN effect. Little and seldom changes were observed in HBeAg and anti HBc serum levels. The profiles of HBsAg serum levels of interferon-treated patients compared with the profiles of "conventionally" treated patients disclosed occurrence of spontaneous or perhaps interferon-induced cyclic elevations and depressions of HBsAg blood levels. The possible significance of this phenomenon is discussed.

Adult↗
PubMed1988

A simple novel procedure for preparation of herpes simplex virus subunit vaccine.

A simple procedure for preparation of herpes simplex virus type 1 (HSV-1) subunit vaccine is described. The method is based on treatment of virus-infected cells with a nonionic detergent, removal of cell nuclei by low speed centrifugation, separation of viral nucleocapsids by high speed centrifugation through a sucrose cushion and, finally, precipitation of viral and cellular glycoproteins and proteins with ammonium sulphate (AS). Unlike to acetone precipitation, affinity chromatography on lectins or hydroxylapatite chromatography, AS precipitation repeatedly yielded the best and most reliable results as judged by relative protein content, antigenicity and immunogenicity of the final vaccine product.

Ammonium Sulfate↗
PubMed1983

Interferon as therapeutic agent.

The article summarizes the present status of interferon (IFN) research from therapeutical point of view. This includes its understanding as an antiviral agent and a cell regulator of hormonal- and/or cytokine-type. The IFN seems to represent a part of a balanced multisystem of unsharp contoures. In addition to the analysis of published therapeutical trials, the conclusion is made that without a deeper insight in the functioning of this system, it is difficult to create a rational base for IFN therapy of viral, oncological and/or autoimmune diseases of man.

Animals↗
PubMed1980

The cell growth inhibitory and antiviral effects of interferon in cloned transformed mouse cells.

Eight clones and two subclones of SV40- and seven clones and one subclone of 20-methylcholanthrene-transformed C3H mouse embryonic fibroblasts were compared in tests for sensitivity to the antiviral and cell-growth inhibitory activities of a partially purified mouse L-cell interferon. While the sensitivity of clones and subclones to the antiviral activity of interferon was comparable to that of parent lines, the cell-growth inhibitory activity of interferon in the SV40 clones showed more than 100-fold variation and the methylcholanthrene-transformed cells could be divided into two groups in this respect. No correlation of sensitivity to the cell-growth inhibitory effect of interferon with the chromosome number, interferon-producing capacity or tumorigenicity of the clones could be detected. However, the cells of the interferon-sensitive clones No. 36 of the methylcholanthrene-transformed line were destroyed by macrophages at higher percentage binding of 125I-labeled soybean lectin. These results suggest that (1) the cell-growth inhibitory effect of interferon might be mediated by a specific type of receptors, and (2) N-acetyl-galactosamine present on the surface of interferon-resistant cells in a higher concentration than on interferon-sensitive cells hinders the recognition of cells both by macrophages and by interferon.

Animals↗
PubMed1979

Production of human leukocyte interferon for clinical use under immunoelectrophoretic control.

Human leukocyte interferon (HLIF) can be contaminated by several antigens which may include also potentially pathogenic agents. For this reason, gel filtration as a separation method was included into the routine procedure of preparation and purification of HLIF for clinical use. Since production of HLIF requires the cultivation of leukocytes in the presence of serum (or albumin), serum proteins represent then the majority of proteins contaminating IF preparations. Measuring the total protein content, as a control of various antigens present in HLIF preparations during purification, becomes ineffective because, essentially, it indicates only the decrease of the amount of proteins derived from cultivation medium. For a better visualization of dissociation of different antigens from molecules with IF activity during the purification procedure, the method of quantitative immunoelectrophoresis was applied utilizing a sheep antiinterferon serum in assay. Our results indicate that this method represents a valuable control test.

Animals↗
PubMed1979

Decrease of sensitivity to cell-growth inhibitory effect of interferon in human embryo cells after infection with SV40.

No changes in sensitivity of human embryo cells (HEC) to the antiviral action of interferon early (i.e. up to 17 days) after infection with simian virus 40 (SV40) could be detected. At the same time the sensitivity of cells to the cell-growth inhibitory effect of interferon decreased considerably. The changes in sensitivity of HEC to interferon action occurred during 5 successive passages following the infection with SV40 and remained on a similar level thereafter. During this period, no morphological alterations of cells were observed.

Cell Division↗
PubMed1978

Quantitative immunoelectrophoresis of human interferon. A new approach to characterization of interferon preparations.

The electroimmunoassay (quantitative "rocket" immunoelectrophoresis) method was adopted for analysis and characterization of interferon preparations. Ammonium sulphate-precipitated anti-interferon globulin also containing unknown antibodies against antigens that contaminate interferon preparations was used in the tests. By comparing the results of the electroimmunoassay of fractions obtained by polyacrylamide gel electrophoresis of human leukocyte interferon with the antiviral activity of the fractions, an excellent dissociation of molecules with interferon activity from the bulk of contaminating antigens was achieved. The method is extremely sensitive and requires very small volumes for assay.

Electrophoresis, Polyacrylamide Gel↗
PubMed1977

The cell-growth inhibitory effect of interferon. Studies of a resistant cell-subline.

Studies performed in the CSV subline of mouse L-cells suggest that activated endogenous and/or exogenous viral infection might be the factor that modifies the cell surface and, in consequence, the sensitivity of the cell to the cell-growth inhibitory action of interferon. In contrast with the parental L-cells, the CSV subline obtained by prolonged passage of L-cells in the presence of interferon shows an altered electron microscopic morphology, absence of C type particles and a decreased agglutinability with Concanavalin A. It is resistant to the cell-growth inhibitory effect of interferon but retains the sensitivity toward its antiviral effect. However, the sensitivity of the CSV subline toward the cell-growth inhibitory effect of interferon increased significantly after treatment with 5-iododexyuridine, infection with the Harvey strain of mouse sarcoma virus and/or prolonged passages in vitro. In this respect, the CSV subline resembles the primary mouse embryonic cells. Since sensitivity of CSV cells increased also after treatment with cyclic 3'-5' adenosine monophosphate and/or prostaglandin E2, it is possible that the cell-growth inhibitory effect of interferon is mediated through the "second messenger" system.

Animals↗
PubMed1977

Purification of mouse interferon on specifically purified immunoadsorbent.

A one-step purification procedure using affinity chromatography on purified anti-interferon antibodies makes possible to obtain highly purified interferon preparations. Antibodies against purified mouse fibroblast interferon were covalently bound to activated CNBr-Sepharose 4B. This immunoadsorbent had a binding capacity of 125,800 mouse fibroblast interferon units per 4.8 ml of gel. The binding capacity for mouse leukocytes was similar while for serum interferon it was lower. When analyzed in polyacrylamide gel, the electrophoretic profiles of purified IF had a similar shape to that of unpurified IF. The results of this purification procedure are not influenced by volume, biological activity and/or purity of the starting material.

Animals↗
PubMed1977

Some biological activites of rabbit anti-interferon serum.

After prolonged immunization of rabbits with a semipurified mouse interferon preparation in Freund-incomplete and/or Al-Span-Oil-adjuvant a specific interferon neutralizing immunoglobulin was obtained from antiserum. The specific activity of the antiserum and immunoglobulin was confirmed in tests in which the interaction of antibodies with the cell-surface was ruled out. The antiserum (and the immunoglobulin) neutralized both the anti-viral and the cell-growth inhibitory activity of interferon. The "slow" and the "fast" fractions of purified interferon preparations were equally sensitive toward the neutralizing effect of antibodies. On the other side, the reaction of heat-inactivated interferon with the antiserum did not diminish its neutralizing activity suggesting a destruction of interferon-antigenic sites.

Immune Sera↗
PubMed1976

Some biological activities of rabbit anti-interferon serum.

After prolonged immunization of rabbits with a semipurified mouse interferon preparation in Freund's incomplete or Al-Span-Oil adjuvant, a specific interferon-neutralizing immunoglobulin was obtained from antiserum with a capacity of neutralizing about 49000 mouse interferon units per ml. The specific activity of the antiserum and immunoglobulin was confirmed in tests in which the interaction of antibodies with the cell surface was ruled out. The antiserum (and the immunoglobulin) neutralized both the antiviral and the cell-growth inhibitory activities of interferon. The "slow" and the "fast" fractions of purified interferon preparations were equally sensitive to the neutralizing effect of antibodies. On the other hand, the reaction of heat-inactivated interferon with the antiserum did not diminish the neutralizing activity of the latter, suggesting a destruction of interferon antigenic sites.

Animals↗
PubMed1976

Affinity chromatography of mouse interferon: a modified purification procedure utilizing specifically purified antibodies.

Interferon preparations of a high degree of purity were obtained by a one-step procedure using affinity chromatography on specifically purified immunoadsorbent. The procedure consisted of binding interferon harvested from serum-free medium and purified by Zn-acetate precipitation and SP-Sephadex chromatography to CNBr-activated Sepharose 4B (Column No. 1). In the next step, antiinterferon globulin was purified by affinity chromatography on Column No. 1 with the bound interferon. In this way, antibodies against purified interferon, which were free from non-antibody components, were obtained. The purified antibodies were then coupled to CNBr-activated Sepharose 4B forming Column No. 2. The latter had a binding capacity of 125 800 mouse interferon units per 4.8 ml of gel. This capacity was not altered during an 8-month period of use. The gel was capable to bind interferons obtained from fibroblasts and leukocytes and, partially, from serum. The resulting purified, products were similar, i.e. they were not influenced by volume, interferon activity, or purity of the starting material. The electrophoretic profiles of the products had a similar shape irrespective of the origin of the starting material.

Animals↗