Microcalorimetric assessment of liquid culture media.

Microcalorimetry constitutes an analytic tool to register the heat effects produced by the metabolic processes taking place in a bacterial culture. Since these depend on the nutrients supplied in the media, microcalorimetry allows conclusions to be drawn about the nature and quality of the culture medium when using a standard germ. Taking Columbia Broth as an example, we showed that faulty weighing of the dry substrate, incorrect pH or overheating during the dissolving or autoclaving procedures could be detected by the use of the microcalorimetry.

[Detection of antibodies to HTLV-III: a comparison of various ELISA methods as screening tests and the Western Blot with immunofluorescence as confirmatory procedures].

386 sera were examined with three commercially available ELISAs for antibodies to HTLV-III. Western Blot and an indirect immunofluorescence assay were performed on sera showing a positive reaction in one or more ELISAs as confirmatory assay. 299 sera reacted negatively in all ELISAs, 48 were positive in all ELISAs and the confirmatory assays, whilst 33 ELISA positive sera reacted negatively in the confirmatory assays.

Involvement of complement in B-cell, T-cell and monocyte/macrophage activation.

In the early 70's it had been shown, that for the immune response against T-dependent antigens C3 was necessary, while T-independent antigens, although activating the alternative pathway of complement, triggered antibody formation also in C-deficient mice. During recent years functional and biochemical knowledge about complement binding structures on B-cells and monocytes/macrophages continuously increased and, also, on T-cells C3 binding entities have been detected. In the case of B-cells and, at least in special experimental conditions, in the case of T-cells C3 can exert a proliferative response as long as the cells are prestimulated (excited) by anti-Ig or IL-2, respectively.

Activated T cells in addition to LAV/HTLV-III infection: a necessary precondition for development of AIDS.

Urinary neopterin levels are raised with a high incidence in all risk groups for AIDS. Neopterin elevations reflect activated cellular immunity in risk group members, in some cases independently of LAV/HTLV-III infection. Moreover, we are able to show that in patients receiving multiple blood transfusions at least a transient challenge of cell-mediated immunity occurs, which is indicated in part by increasing neopterin levels.

[Effect of long-term preventive use of TMPS on the composition and resistance behavior of aerobic fecal flora].

Trimethoprim Sulfa is a valuable agent in the prophylaxis of Pneumocystis carinii pneumonia in immunocompromised children. Like several other antimicrobial substances also TMPS has an impact on the normal bacterial flora of children. TMPS sensitive enterobacteria are eliminated from the gut flora within 48 hours.

[Microcalorimetric study of Salmonella].

We investigated the heat production of 42 different Salmonella strains belonging to the serogroups A, B, C, D and E. Using Columbia- and Brain Heart Infusion Broth as growth media, we found 3 different types of heat profiles. Salmonella typhi and Salmonella choleraesuis showed thermograms which differed in shape from the remaining serotypes.

Cell cycle control of activated, synchronized murine B lymphocytes--roles of macrophages and complement C3.

Three restriction points control the cell cycle of activated murine B lymphocytes in a synergistic way. The first is controlled by the occupancy of surface immunoglobulin either by antigen- or by immunoglobulin-specific antibodies. The second is controlled by the complement C3d receptor CR2 which can be occupied by cross-linked C3b or C3d to stimulate the entry into S phase, or by soluble C3d or a C3 alpha-chain peptide, binding to the CR2 receptor, which inhibit the entry into S phase.

Human complement factor H: isolation of cDNA clones and partial cDNA sequence of the 38-kDa tryptic fragment containing the binding site for C3b.

We isolated cDNA clones coding for the functionally important tryptic N-terminal 38-kDa fragment of human complement control protein factor H using polyclonal and monoclonal antibodies to screen a human liver cDNA library cloned in a bacterial expression vector, PEX-1. By testing the reactivity of antibodies specific for the recombinant proteins produced by individual clones with proteolytic fragments of serum H the exact position of these cDNA clones within H was mapped. One clone, H-19, coding for the 38-kDa fragment of H was sequenced and found to code for 289 amino acids derived from the 38-kDa N-terminal fragment as well as for the first 108 amino acids belonging to the complementary 142-kDa tryptic fragment.

Use of a high-efficiency expression vector to isolate cDNA clones for factor H and map their positions within the molecule.

A human liver cDNA library, cloned in a novel high-efficiency bacterial expression vector (PEX), was screened with an affinity-purified antibody to human factor H. Four distinct cDNA clones, H-2, H-40, H-46 and H-49, were identified. Of these, H-2 also reacted with two monoclonal antibodies to H, MAH-4 and OX-24, which were previously shown to recognize the 38,000 N-terminal tryptic fragment of H, carrying the binding site for C3b.

Receptors for the third component of complement: their association with maturation stage in non-Hodgkin lymphomas (NHL) and their possible implication with the development of follicular structures.

In the majority of 188 non-Hodgkin lymphomas (NHL) investigated in this study, we found a simultaneous expression of the receptors for c3b and c3d (CR1 & CR2; cccorr = 0.69, P less than 0.0005).

[Antibody titer to Bacteroides fragilis is increased in Crohn disease patients with fistula development].

We compared antibody levels to Bacteroides fragilis in patients with different stages of Crohn's disease and ulcerative colitis to normal controls using an ELISA. IgM-titers were low in patients with Crohn's disease who had undergone surgery of small or large bowel but normal in all other groups of patients. Similarly, IgG-titers were similar to control values in all patients with uncomplicated Crohn's disease but elevated in patients with complicating fistula, colonic Crohn's disease and resected small or large bowel.

Influence of cephalosporines III generation with varying biliary excretion on fecal flora and emergence of resistant bacteria during and after cessation of therapy.

Excretion of an antibiotic bile may result in high intraintestinal concentrations and thus alteration in the fecal flora. We investigated the effect of ceftriaxone (45% biliary excretion) and cefotaxime (less than 5% biliary excretion) on the aerobic fecal flora. Ceftriaxone eradicated susceptible enteric organisms and resulted in overgrowth of Candida spp.

Herpes simplex virus type 1 and 2 in the adrenal glands: replication and histopathology.

The adrenal glands were shown to be the most severely infected organs in the early phase of HSV-1 infections (up to 10 days p.i.) after i.

Structural and functional analysis of the complement component factor H with the use of different enzymes and monoclonal antibodies to factor H.

The action of six different enzymes on the function and structure of Factor H was investigated by use of sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, haemagglutination, two enzyme-linked immunosorbent assay systems and an assay for Factor I cofactor activity. Six monoclonal antibodies directed against the 38 kDa tryptic fragment of Factor H [which contains the binding site for C3b (a 180 kDa fragment of the third component of complement) and the cofactor activity] were also used to detect cleavage products derived from the same fragment. Elastase, chymotrypsin A4 or trypsin first cleaved Factor H to 36-38 kDa fragments carrying all six monoclonal anti-(Factor H)-binding sites.

Candida albicans and Candida stellatoidea, in contrast to other Candida species, bind iC3b and C3d but not C3b.

It was demonstrated that complement-coated sheep erythrocytes bind to Candida albicans cells grown in serum-free RPMI 1640 medium. Testing of purified complement components proved that iC3b and C3d were responsible for the reaction, whereas C3b and C3b-H reacted only slightly if at all. Binding occurred only to C.

[Demonstration of antibodies against Bacteroides fragilis in children using ELISA].

The ability of children to produce antibodies to B. fragilis shortly after birth was demonstrated by means of the ELISA technique. After half a year they have titres similar to adults.