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Biomedical subjects

T Montag

Publications and source records attributed to T Montag.

33 records · Page 2Linked to original sources

[A fermenter dialysis cultivation technic for encapsulated pathogenic bacteria. II. Group B streptococci].

For mass cultivation of group B streptococci (B-III and B-variant streptococci), a fermenter dialysis culture technique is described and compared to conventional shaking culture and fermenter batch culture techniques. The influence of two kinds of cultivation media on the bacterial yield is demonstrated. The growth rate of the bacteria and the yield of the microbes is higher in modified POPE medium than that observed with Nährbouillon I. The type-specific polysaccharide of B-III-streptococci prepared by phenol-water extraction followed by gel-chromatography can be used as a screening antigen for the production of monoclonal antibodies against B-III-streptococci.

Antigens, Bacterial↗

Interactions between Sarcocystis gigantea lectin and toxin-containing fractions in human lymphocyte cultures.

Sarcocystis gigantea extract (SGE) was separated by affinity chromatography into one lectin-containing fraction (SGL) that was mitogenic to mononuclear cells (MNC) and another that lacked this lectin activity. The SGL-depleted Sarcocystis extract (SGTF) contained the so-called Sarcotoxin, inducing only a slight increase in MNC proliferation. Furthermore, preincubation of MNC with SGTF for 60 min suppressed the mitogenic capacity of SGL by 60%-90%. The results presented indicate that SGTF interacts with human MNC differently than SGL, particularly by interfering with the mitogenic lectin. These findings suggest that SGL and SGTF may be involved in different immunomechanisms induced by the parasite.

Animals↗

[The protein pattern of Gasterophilus intestinalis larva (Diptera: Gasterophilidae), Psoroptes cuniculi and Chorioptes bovis (Acarida: Psoroptidae)].

SDS-PAGE and chromatography of the mange mites Chorioptes bovis and Psoroptes cuniculi and Gasterophilus intestinalis instars revealed a species and stage specific distribution of proteins. This specific protein pattern is responsible for an immune response depending on the course of the parasitic infection. Therefore, identification and isolation of the adequate antigens are necessary for diagnostic purposes.

Animals↗

Polyclonal IgG synthesis of mononuclear cells induced by the homopolymer of 4,6-dideoxy-4-formamido-alpha-D-mannopyranosyl units isolated from Brucella melitensis.

Brucella melitensis attaches selectively to B lymphocytes. The bacterium induces in vitro only a slight proliferation of mononuclear cells and inhibits the spontaneous IgG synthesis. In order to characterize these effects, the O-chain of the lipopolysaccharide of Brucella melitensis (a polysaccharide consisting of poly-4,6-dideoxy-4-formamido-alpha-D-mannoside) was prepared and its influence on lymphocyte functions tested. This compound had no effect on blast transformation whereas IgG synthesis of the cells was stimulated more than tenfold by the addition of the Brucella polymannoside.

Antibody Formation↗

[Mineral content of the spongiosa of the lumbar spine determined by computer tomography. Normal values for healthy perimenopausal women and their relation to mechanical stress of the vertebral column].

Healthy perimenopausal women (152) were examined by QCT to quantify the mineral content of the axial skeleton. The density was measured in the spongiosa of the L2-4, using single energy technique and the Cann-Genant calibration phantom. The women, aged 37 to 64, had no history of pathological fractures, ovariectomy, metabolic disease, or hormone therapy. The age-related mean values were 25 mg K2HP04/cm3 lower than the normal values reported by Genant et al. for 203 healthy American women. The 95% confidence interval was distinctly narrower (+/- 40 mg/cm3) than the American confidence interval (+/- 60 mg/cm3). To evaluate the relationship of the BMC to mechanical stress, the BMC was compared with body weight, body mass index (weight/height2), and the lumbar muscle mass estimated from cross sections of the paravertebral muscles in the CT images. The assumption that higher mechanical stress results in higher bone mineralization could not be confirmed.

Adult↗

Influence of autoclaved Brucella melitensis on the proliferation of human lymphocytes.

Brucella melitensis is a facultative intracellular bacterium which binds spontaneously to human B-lymphocytes. In order to find out whether there exists a relation between bacterial adherence and lymphocyte reactivity, the proliferation response of normal adult peripheral blood lymphocytes to autoclaved B. melitensis has been studied. Our results indicate that autoclaved B. melitensis induce only a slight increase in proliferation. This low lymphocyte response is due to proliferating B-cells. In high doses B. melitensis inhibited the response of lymphocytes to Concanavalin A and phytohaemagglutinin. This effect is probably due to the presence of lectin binding saccharides on the bacterial surface competing with the T-cells for the mitogens.

Adult↗

Extracts from Sarcocystis gigantea macrocysts are mitogenic for human blood lymphocytes.

Extracts were prepared from macrocysts of Sarcocystis gigantea, an animal parasite, by sonication and high speed centrifugation. Mononuclear cells were obtained from the blood of 14 adults and 5 newborns and used for transformation assays. Addition of Sarcocystis extracts (equivalent to 400 micrograms protein/ml) to these cells increased the lymphocyte proliferation approximately 71 fold over the background. The control with Pokeweed mitogen (5 micrograms/ml) gave a stimulation index of 58. There was no difference in the response to the Sarcocystis extract between the lymphocytes of adults and those of newborns. This findings show that the effect of the extract is mitogenic and not due an anamnestic reaction.

Adult↗

The use of glass as solid phase in enzyme immunoassay as exemplified by the detection of circulating immune complexes.

This article describes a solid-phase enzyme immunoassay for the quantitative determination of circulating immune complexes based on the covalent binding of proteins to glass. A quantitative comparison between adsorption to polystyrene and covalent binding to glass gave a protein higher concentration on the glass support. This leads, in connection with the strong attachment of the protein, to a higher sensitivity and precision in immunoassay. The binding of C1q to glass as solid phase offers the possibility to reuse the protein as well as the glass support after accomplishment of the immunoassay which can reduce the cost of the assay in routine work dramatically. Furthermore, the immobilization of C1q to glass gives an extreme stability of the protein which means that the c1q-coated glass supports can be used up to one year under routine conditions.

Adsorption↗