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Biomedical subjects

M Schlaak

Publications and source records attributed to M Schlaak.

At least 163 records · Page 9Linked to original sources

[Vasculitis and granulomatosis in the respiratory tract].

Lately new aspects of diseases have been described in long known forms of pulmonary vasculitis and granulomatosis like Wegener's granulomatosis (WG), sarcoidosis (SA), exogenous allergic alveolitis and the Churg-Strauss syndrome. In WG it is clinically important to distinguish between two different phases of disease - the early initial phase with localized inflammation and granuloma formation and the later generalized form of disease where an involvement of virtually every organ system can occur. Recently autoantibodies (antineutrophil cytoplasmic antibodies) have been discovered which are highly specific for WG and additionally are helpful to determine the activity of the disease. With respect to both findings and more recent experience with various therapeutic regimes a therapy considering the phase and activity of disease is recommended. In SA the analysis of the bronchoalveolar lavage has not only led to a immunodiagnostic concept but also given immunopathogenic insights. In contrast to former ideas the SA is not the consequence of an anergic state but more likely of an increased activity of the immune system which is hinted at by the finding of activated CD4-positive lymphocytes in the interstitial tissue and lavage fluid. In exogenous allergic alveolitis new disease concepts are arising from the better understanding of the triggering agents which can now be better analysed.

Alveolitis, Extrinsic Allergic↗

Conventional isoelectric focusing does not dissociate immune complexes.

Contrary to some reports, isoelectric focusing (IEF) is unable to dissociate immune complexes (IC) into their constituent components. Six model IC systems prepared at various antigen/antibody ratios were readily dissociated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), but not by conventional IEF, independently of several modifications of the running conditions. IC preformed in situ in the IEF gel were not disrupted by subsequent electrophoresis. Moreover, formation of IC was demonstrable in IEF, when applying antigen and antibody preparations in the manner used for counterimmune electrophoresis. Nevertheless, IEF may be of value in the analysis of IC provided the complexes are of small enough size to enter the gel.

Animals↗

Homogeneous immunoglobulins in the sera of lung carcinoma patients receiving cytotoxic chemotherapy--detection with the use of isoelectric focusing and immunoblotting.

Using isoelectric focusing (IEF) with immunoblotting, we have analysed serum immunoglobulins of 15 lung cancer patients on cytotoxic chemotherapy. In five of the patients homogeneous immunoglobulins were found which appeared between 9 and 18 months after beginning of treatment and were monoclonal in two and oligoclonal in three cases. These abnormalities were only partially shown by zonal electrophoresis with immunofixation and not detected by immune electrophoresis. Examination of 10 normal and 10 myeloma sera by the three techniques in parallel confirmed the competence and sensitivity of IEF with immunoblotting in detecting homogeneous immunoglobulins. Thus, this method provides a valuable tool for investigating an abnormal regulation of the immunoglobulin synthesis.

Aged↗

Analysis of allergen components in grass pollen extracts using immunoblotting.

Sera of 60 allergic persons and 20 healthy RAST-negative control persons were examined using immunoblotting to establish the presence of grass pollen-specific antibodies. These antibodies were depicted by an enzymatic, immunoglobulin class-specific indicator system. Seven bands of the timothy pollen extract proved to be major allergens. One of the 4 grass pollen-specific monoclonal antibodies tested (Bo 1) recognized the 7 major allergen bands. The possibility of employing monoclonal antibodies for the isolation of allergens is discussed.

Animals↗

Modulation of human lymphocyte functions by group A streptococci.

Intact (heat-inactivated) bacteria and isolated cellular components of pathogenic group A (M type 5 or 12). B. C. and G streptococci were used to evaluate the in vitro reactivity of mononuclear cells (MNC) from peripheral blood of healthy donors and from human tonsils. High doses of A-streptococcal cells, cell walls, and cell membranes stimulated DNA synthesis, production of leukocyte migration inhibitory factor (LIF), and immunoglobulin (Ig) secretion in MNC from all donors. A streptrococci stimulated higher proliferation rates and larger numbers of plaque-forming cells (PFC) in tonsil cell cultures than in blood MNC cultures. Polyclonal activation of both tonsil and blood B lymphocytes by A-streptococcal cell components was T cell and monocyte dependent, thus showing a similarity between these structures and pokeweed mitogen (PWM), which is a polyclonal T-cell activator (PTA). Cocultivation studies demonstrated that, in the presence of A streptococci, precultured MNC and T cells can suppress the blastogenic and PFC responses of autologous fresh MNC stimulated by phytomitogen or antigen, which is very similar to the concanavalin A (Con A)-induced activation of suppressor cells. In contrast, similar group B-, C-, and G-streptococcal cell envelope biostructures failed to activate blood or tonsil lymphocytes to proliferate, differentiate, or produce LIF.

Adult↗

[Circulating immune complexes and NK activity in systemic lupus erythematosus].

NK-activity of normal mononuclear cells is inhibited in vitro by addition of immune complexes or aggregated IgG. We therefore studied 20 sera of patients with systemic lupus erythematosus in order to investigate whether there is any correlation between the presence of circulating immune complexes and suppression of NK-activity. A correlation was not found.

Antibody-Dependent Cell Cytotoxicity↗

HLA-related lymphocyte responsiveness in psoriasis.

In order to find associations among the genetic, immunological and environmental factors that might be important in the pathogenesis of psoriasis, the relationship between streptococcal antigen- or mitogen-induced lymphocyte responses in vitro and HLA phenotypes was studied in 23 patients with psoriasis. Patients showed an elevated lymphocyte response to somatic A-streptococcal antigens when compared with healthy controls. In contrast, the response to mitogens (PHA, Con A, PWM) was impaired in patients with psoriasis. The impaired mitogen-induced lymphocyte transformation was found mostly in psoriatics with HLA-B13/B17. The elevated cellular immune response to somatic A-streptococcal antigens, on the other hand, was observed mainly in psoriatics without HLA-B13/B17. The results indicate that gene products of the HLA region known to be associated with psoriasis are involved in the cellular immune response, as expected from clinical trials. These findings also provide further evidence of at least two different subtypes of psoriasis, characterized by genetically and immunologically defined markers.

Antibodies, Bacterial↗

[Efficiency of current technics for the isolation of viruses in water].

In an attempt to evaluate the efficiency of the current methodology for the concentration of viruses from water and wastewater, we have determined the viral concentration in raw sewage using three procedures: a) inoculation of cell cultures directly with the filtered sewage, b) concentration of the viruses from the sewage using nitrocellulose filters at a pH of 3.5 in the presence of AlCl3, followed by elution with Nutrient Broth and inoculation of the cell cultures with the eluant and c) flocculation of the Nutrient Broth after the elution as in b, dissolution of the precipitate in cell medium and inoculation of the cell cultures with this solution. The results show that this concentration procedure with nitrocellulose filters as recommended in the "Standard Methods for the Examination of Water and Wastewater" has an efficiency of 33% if compared with the direct inoculation. In a separate study, we have looked at the properties of electropositive Filters to bind polioviruses Typ I, Strain Lsc 2ab at neutral pH in the absence of salt. These filters, which could be used several times, were able to retain more then 99.5% of the viruses. However, they bound the viruses stronger that nitrocellulose filters and the elution with Nutrient Broth was never complete. After the problems with the elution are solved, these filters promise to simplify substantially the procedure for concentrating viruses from water.

Collodion↗

[Streptococcal A-induced polyclonal T-cell activation leads to a secondary functional activation of human B-cells].

Human lymphocytes are activated by cell walls or cytoplasma membranes of A-streptococci. Even in health human volunteers lymphocyte proliferation, lymphokine production and immunoglobulin synthesis is induced by high concentrations of streptococcal cell components following a pattern of polyclonal lymphocyte activation. We were interested in the special cellular requirements in this particular model. In cell separation and restitution experiments the observed B-cell activation was identified as the consequence of a primary monocyte-dependent polyclonal T-cell activation. Furthermore, lymphocyte proliferation and lymphokine production proved to be a monocyte- and T-cell-dependent process as well. Thus, lymphocyte activation induced by somatic streptococcal structures in humans depends upon a pattern of cell cooperation of mononuclear subpopulations well-known in a series of classical mitogen-induced lymphocyte activation.

Antigens, Bacterial↗

Left hepatic lobe atrophy and partial Budd-Chiari syndrome in a patient with alcoholic liver cirrhosis.

The unusual association of alcoholic liver cirrhosis, atrophy of the left hepatic lobe and endophlebitis of the left hepatic vein (partial Budd-Chiari-Syndrome) has been observed in a 72-year-old male. The atrophy of the left hepatic lobe was diagnosed by liver scanning and laparoscopy. The patient's condition finally deteriorated and he died in a chronic form of hepatic coma. At autopsy the right hepatic vein, the branches of the portal vein and the extrahepatic bile ducts were normal. The left hepatic vein showed the histological picture of an organized endophlebitis of indeterminate age.

Aged↗

Detection by immunofluorescence of a new "core-like" Ag/Ab system in liver and serum of patients with NANB hepatitis.

Using direct immunofluorescence, a nuclear antigen was found in liver of chronic hepatitis patients with circulating NANBe Ag or anti-NANBe, and selected sera from either group were used as source of conjugates. The new Ag/Ab system was designated NANBc Ag and anti-NANBc since it behaved like the core Ag of HBV . NANBc Ag was detected in coded frozen liver biopsies from patients with chronic persistent 15/25 (60%) or active 27/50 (54%) hepatitis and cryptogenic cirrhosis 16/30 (53.3%) devoid of HBV markers. Only 2/30 alcoholic cirrhosis cases (7%) used as controls were positive (p less than or equal to 0.001). The homologous anti-NANBc antibody was always detectable by indirect immunofluorescence in the patients' serum when NANBc Ag was found in the liver. It was also found in 11/135 (8%) additional cases without any other NANB marker. A correlation was observed between coded detection of the NANBc Ag/Ab system by immunofluorescence and demonstration of NANBe Ag or anti-NANBe by immunodiffusion. In acute post-transfusion NANB hepatitis, anti-NANBc was first detectable 14 days after transfusion and persisted as long as ALT remained elevated, or longer. IgM anti-NANBc present at onset became associated with an increasing proportion of IgG after the 28th day. The prevalence of anti-NANBc in sporadic NANB hepatitis (11/50 = 22%) was significantly lower (p less than or equal to 0.001) than in cases with parenteral exposure such as post-transfusion, occupational or drug addict hepatitis (47/72 = 65%). Immunofluorescent tests for NANBc Ag and Ab are promising assays for the serological diagnosis of NANB hepatitis.

Antibodies, Viral↗

Purification and characterization of human bone marrow lymphocyte subpopulations: evidence for the existence of an alloreactive immature T cell.

This study was conducted in order to clarify further the role of bone marrow lymphocyte (BML) subsets in graft-versus-host disease (GVHD) after clinical BM transplantation. Human BML separated by velocity sedimentation through a continuous sucrose gradient were found to consist of 38% T, 21% B and 41% null cells. T cells were purified from BML or peripheral blood lymphocytes (PBL) by rosette formation with sheep red blood cells (SRBC) and subsequent gradient centrifugation. Mitogenic stimulation of BML, PBL and the respective T cell subsets revealed the well-known reactivity of mature T lymphocytes, whereas non-T lymphocytes comprising T cell precursors showed only a weak response. In allogeneic stimulation kinetics, however, non-T-BML disclosed a delayed but marked responsiveness as compared to BML and T-BML suggesting that a T cell precursor matures under culture conditions. This cell type could be involved in GVHD in addition to mature T cells after clinical bone marrow transplantation.

Bone Marrow↗

[Clinical features and treatment of Wegener's granulomatosis (author's transl)].

Between 1972 and 1978 a total of 16 patients, aged 19 to 70 years, seven of them women, were diagnosed as having Wegener's granulomatosis. The course of the disease in some instances was rapidly progressive, in some protracted. Nine patients have died, three of them within three months. The diagnosis can only be made after intensive ear-nose-throat, medical and histological studies. Early administration of cyclophosphamide seems to influence the course of the disease favourably.

Adult↗