Biomedical subjects

C Ruedl

Publications and source records attributed to C Ruedl.

28 records · Page 2Linked to original sources

PubMed1995

Chronic granulomatous disease assessed by single-cell granulocyte oxidative burst activity.

Here we report on a case of chronic granulomatous disease (CGD) in a 3-year-old boy who suffered from severe repeated bacterial infections including multiple liver abscesses. The case is of interest because (1) the disease is very rare (it is the first case of CGD diagnosed at the Clinic for Pediatric Medicine, University of Innsbruck), (2) the diagnosis, based on clinical parameters and the nitrobluetetrazolium test was completed and validated by single-cell measurements of respiratory-burst activity of the patient's granulocytes in a fluorescence-activated cell sorter (FACS), and (3) the applied FACS method, adapted in our laboratory, presents one of the most sensitive and reliable methods to evaluate this aspect of disturbed granulocyte function.

Cell Separation↗

PubMed1995

Features of oral immunization.

In this review, we focus on some key areas concerning the unique properties of the mucosal immune system. They are: (1) the fact that the common mucosal immune system consists of different compartments; (2) the advantages of oral vaccination, which can be exploited to antigen-specific sIgA-mediated local immune responses as well as systemic immunity; (3) efficacious oral immunization against respiratory infections; (4) oral tolerance with respect to activation of T cells which, after declining, can be repeatedly reinduced without changes in profile or magnitude, and (5) the use of transgenic plants as a new vaccine source for a new vaccination strategy, i.e. employing edible dietary vaccines.

Administration, Oral↗

PubMed1994

A novel and sensitive method for the detection of secreted cell products using time-resolved fluorescence.

A new test has been developed for the quantitative detection of products secreted from isolated cells, based on the use of lanthanide- rather than enzyme-linked streptavidin. Used as a label, europium (Eu3+) can be measured with high sensitivity by time-resolved fluorescence. The main advantages of this assay are both an increased sensitivity and measuring range of cell released substances, when compared to the standard "wet" ELISA. Thus, the immunoglobulin secretion rate of 10(5) splenocytes could be easily measured by time-resolved fluoroimmunoassay (TR-FIA), while it remained below the detection limit of the 'wet' ELISA. In contrast to the classical ELISPOT test, this assay does not detect single antibody secreting cells (ASC), but would be useful for precise quantification of secreted cell products, such as immunoglobulins, cytokines, growth factors.

Animals↗

PubMed1994

Immune response in the lungs following oral immunization with bacterial lysates of respiratory pathogens.

We have investigated the local immune response of the BALB/c mouse respiratory tract after oral immunization with a bacterial lysate of seven common respiratory pathogens. After two immunization on five consecutive days, we examined the immunoglobulin (immunoglobulin G [IgG], IgM, and IgA) secretion rates of cells isolated from the lungs and compared them with those of spleen cells of orally immunized and nonimmunized animals by using a new test system based on time-resolved fluorescence. The procedure followed the principle of the classical ELISPOT test with nitrocellulose-bottomed microtiter plates, but europium (Eu3+)-linked streptavidin rather than enzyme-conjugated streptavidin was used, with the advantage of quantifying secreted immunoglobulins instead of detecting single antibody-secreting cells. Lymphocytes isolated from the lungs of treated animals revealed significant increases in total and antigen-specific IgA synthesis compared with the rates of the controls, whereas IgG and IgM production rates showed no remarkable differences. In addition, the sera of treated mice revealed higher antigen-specific IgA titers but not increased IgM and IgG levels. We conclude that priming the gut-associated lymphoid tissue with bacterial antigens of pneumotropic microorganisms can elicit an enhanced IgA response in a distant mucosal effector site, such as the respiratory tract, according to the concept of a common mucosa-associated immune system.

Adjuvants, Immunologic↗

PubMed1994

[Enhanced antibody production by lung lymphocytes after oral immunization with Bordetella pertussis surface antigens].

The purpose of our study was to evaluate the effect of oral vaccination with Bordetella pertussis surface antigens on the immune response at the site of antigen application. We orally immunized female BALB/c mice on five consecutive days and repeated this procedure after a free interval of 10 days. Lymphocytes of the lung (LL), Peyer's patches (PPL) and lamina propria of the gut (LPL) were isolated and the immunoglobulin secretion rate was measured with time-resolved immunofluorescence. Oral immunization was found to enhance the IgA secretion rate by 69.9% in LL compared to unimmunized animals. The IgG synthesis in LL was increased by 28.1% and the IgM synthesis by 14.1%. In addition, an improvement of 47.8% was observed for the IgG secretion in LPL and PPL. Thus, our results demonstrate a strong local immune response after oral immunization with Bordetella pertussis.

Administration, Oral↗

PubMed1993

Paracrine interaction in co-culture of hormone-dependent and independent breast cancer cells.

A permeable solid support (Transwell Coll.) was used to develop serum-free co-cultures allowing paracrine interactions between hormone-dependent (MCF-7, ZR75.1) and hormone-independent (MDAMB-231, BT20) breast cancer cell lines. Both hormone-independent cell lines were able to stimulate the growth of the hormone-dependent lines, whereas the opposite was observed only in the case of BT20 co-culture with ZR75.1 cells. The cell growth stimulation observed in co-cultures could be abolished by the addition to the culture medium of an excess of transforming growth factor alpha (TGF alpha) or insulin-like growth factor I (IGF-I). Similarly, treatment with a neutralizing anti TGF alpha antibody impaired the growth stimulation exerted by hormone-independent cells on hormone-dependent cells. These results confirm the important role of paracrine interactions in control of the growth of human heterogeneous breast tumors and suggest that the main growth factors involved in such interactions are TGF alpha and probably some growth factors from the insulin-like growth factor family rather than IGF-I itself.

Breast Neoplasms↗

PubMed1993

Oral administration of a bacterial immunomodulator enhances murine intestinal lamina propria and Peyer's patch lymphocyte traffic to the lung: possible implications for infectious disease prophylaxis and therapy.

LW50020, a bacterial immunomodulator, is a preparation consisting of seven bacteria, commonly causing respiratory disease. When given orally, LW50020 has been shown to enhance the host defense of the respiratory tract. Intestinal lamina propria lymphocytes (LPL), Peyer's patch lymphocytes (PPL), and splenocytes from BALB/c mice gavaged either with LW50020 or carrier alone were isolated, labeled with either H33342, a supravital nuclear fluorochrome, or 51Cr, and injected i.v. into untreated, age-matched BALB/c mice. Two hours later, spleen, liver, lung, kidneys, Peyer's patch, and mesenteric lymph nodes of the recipients were harvested and screened for the presence of labeled cells. LPL from mice gavaged with carrier only (controls) migrated preferentially to the lung, PPL equally well to the lung, and the spleen and splenocytes were found mostly in the spleen. LPL and PPL from LW50020-treated mice were found in significantly larger numbers in the lungs of recipients than LPL and PPL from control animals. Both labeling techniques gave roughly the same results. Sixty-five per cent of LPL in the lung were Thy-1.2+ and 20% B cells. These findings should contribute to the understanding of parameters necessary for the assessment of the mode of action and efficacy of immunomodulation and vaccination via the mucosa-associated lymphoid tissue.

Adjuvants, Immunologic↗

PubMed1991

Interaction between hormone-dependent and hormone-independent human breast cancer cells.

We developed two different models based on in vitro co-culture of hormone-dependent and hormone-independent cell lines to simulate the cell population heterogeneity of human breast cancer tumours. Oestrogen-dependent (MCF-7, ZR 75.1) and oestrogen-independent cell lines (MDAMB-231 BT-20) were grown under serum-free conditions. Co-culture of hormone-dependent and hormone-independent cell lines resulted in an increased cell yield compared to single cell cultures carried out at the same seeding ratios. Such an increase was not affected by addition of oestradiol and single growth factors (EGF, bFGF and IGF-I). These results allow us to conclude that in a heterogeneous cell population like human breast tumours, interaction between hormone-dependent and hormone-independent cell lines may result in a complex regulation of cell growth.

Breast Neoplasms↗

PubMed1990

Influence of culture conditions on the estrogenic cell growth stimulation of human breast cancer cells.

17 beta-Estradiol is a potent mitogen for hormone-dependent cell lines (MCF-7, T47D and ZR 75.1). However, the degree of hormone sensitivity is very much influenced by culture conditions. In order to understand which factors modulate estrogenic effects on cell growth, four different culture conditions were used: (a) medium with dextran-coated charcoal-treated fetal calf serum (DCC-FCS); (b) medium with dextran-coated charcoal-treated growth factor-inactivated serum (DCC-FCSd); (c) serum-free medium, after a 24-h incubation with serum to allow cell attachment; and (d) serum-free medium on collagen IV-treated plates. In all cell lines the highest cell growth stimulation was achieved when estradiol was added in the presence of 5% DCC-FCS, whereas reducing or removing serum from the culture medium resulted in a decrease in cell proliferation stimulation. We postulate that serum contains some still unknown components able to modulate the degree of estrogenic action in endocrine-dependent breast cancer cell lines.

Breast Neoplasms↗

PubMed1989

Differential inhibitory action of the fungal toxin orellanine on alkaline phosphatase isoenzymes.

The inhibitory action of orellanine (3,3',4,4'-tetrahydroxy-2,2'-dipyridyl-1,1'-dioxide), a fungal toxin of Cortinarius orellanus Fr. and C. orellanoides R. Hry., on alkaline phosphatase isoenzymes was studied. Orellanine specifically inhibited alkaline phosphatase activity in LLC-PK1 renal epithelial cell cultures and in the colon carcinoma cell line Caco-2 without affecting gamma-glutamyl transpeptidase activity. Kinetic studies revealed that orellanine acts on renal alkaline phosphatase as a noncompetitive inhibitor, whereas the intestinal and placental isoforms are inhibited competitively.

2,2'-Dipyridyl↗