Search PubMed⌕ Search

Biomedical subjects

E Brummer

Publications and source records attributed to E Brummer.

120 records · Page 7Linked to original sources

A method for eliciting indurated DTH reactions to soluble protein antigens in the flank skin of mice: correlation of visual measurements with 125I-UdR uptake indices.

A new technique for eliciting specific indurated delayed type hypersensitivity (DTH) reactions to soluble protein antigens in the flank skin of mice is reported here. We show that immunization with soluble antigens emulsified in complete Freund's adjuvant emulsion allows elicitation of indurated reactions upon intracutaneous test of sensitized mice with antigen on alum precipitates. With this method it is possible to measure simultaneously the gross induration of the cutaneous DTH reactions and correlate it with the degree of mononuclear cell infiltration as quantitated by the cPM of 125I-UdR uptake in mononuclear cells at biopsied reaction sites and confirmed by histological examination.

Alum Compounds↗

Development of antigen-induced proliferative responsiveness by murine lymph node cells. I. Identification of differences in the in vitro proliferative responses during a first and a second period of responsiveness.

The development and course of antigen-induced proliferative responsiveness by murine lymph node cells (LNC) was observed for 16 weeks post-immunization. The initial phase of responsiveness was characterized by antigen-induced proliferative responsiveness in vitro which reached a maximum 3-5 weeks post-immunization and then declined to low levels by 6-8 weeks. Without injection of additional antigen, the initial phase of responsiveness was followed by the development of a second phase of antigen-induced proliferative responsiveness 10-12 weeks post-immunization. These findings suggest that the in vivo development of lymph node lymphocytes capable of a proliferative response to antigen is under some type of modulation which is maximal 6-8 weeks post-immunization. Early in the first phase the proliferative responses to higher concentrations of antigen peaked early in the culture period (days 3-4), whereas responses to the lower concentrations of antigen were optimal after 5-6 days of culture. During the latter half of the first phase, however, peak proliferative responses were made to all the concentrations of antigen on the same day of culture (day 6). In contrast, the responses detected at the beginning and throughout the second phase of responsiveness were characterized by maximum proliferation to all the concentrations of antigen late in the culture period (day 7). These results delineate the temporal requirements for maturation of antigen-induced proliferative responsiveness of murine LNC post-immunization and indicate the time interval when optimal responses may be detected.

Animals↗

Interaction of subpopulations of murine lymph node lymphocytes in antigen-induced [14C]-thymidine incorporation: T and B cell synergy in the response to antigen.

The antigen-induced [14C]-thymidine incorporation of murine lymph node cells (LNC) that were non-adherent (NAD) or adherent (AD) to nylon wool was studied. In contrast to NAD-LNC, AD-LNC responded like unfractionated LNC, and these responses were T lymphocyte dependent. By co-culturing NAD-LNC with subpopulations of AD-LNC the cellular requirements and interactions necessary for maximal incorporation of [14C]-thymidine were determined. A synergistic effect was observed when NAD-LNC and AD-LNC were co-cultured. Synergism was not dependent on T lymphocytes or macrophages in the AD-LNC population but was associated with the B lymphocyte subpopulation. These results indicate that the number of B lymphocytes present in a population of LNC can significantly influence the magnitude of the response to antigen.

Animals↗

A microculture system for the measurement of antigen-induced murine lymphocyte proliferation: advantages of 5% horse serum and 5 X 10(-5) M mercaptoethanol.

Short term microculture systems which measure murine lymphocyte proliferative responses to mitogens are well established. We demonstrate here that these microculture methods are not suitable for antigen-induced responses because of the high levels of murine lymphocyte proliferation in control cultures associated with the use of fetal calf serum or human serum. We also show that this problem can be eliminated with the use of a combination of 5% horse serum and 5 X 10(-5) M mercaptoethanol. We describe an antigen-induced murine lymphocyte proliferation microculture system in which good stimulation indices are achieved and the lymphocyte proliferation in control cultures remain at a low level throughout the 7 day culture period.

Animals↗

In vitro lymphocyte responses of coccidioidin skin test-positive and -negative persons to coccidioidin, spherulin, and a coccidioides cell wall antigen.

The biological activity of C-ASWS, an alkali-soluble, water-soluble cell wall antigen isolated from mycelial-phase cells of Coccidioides immitis, was compared with that of a commercial coccidioidin (CDN; Cutter Laboratories); CDN-TS, a toluene-induced lysate of mycelial-phase cells; and spherulin, a spherule-derived extract of C. immitis. Lymphocytes obtained from healthy CDN skin test-positive donors (group I), healthy skin test-negative donors (group II), and patients with active coccidioidomycosis (group III) were assayed for lymphocyte transformation and production of macrophage inhibitory factor in response to the Coccidioides antigens. C-ASWS, CDN CDN-TS, and spherulin were each effective in eliciting blastogenic responses in lymphocytes of group I subjects. However, only C-ASWS and CDN-TS were effective in eliciting macrophage inhibitory factor production. The responses of group III subjects (patients) were depressed and, in most instances, were indistinguishable from those obtained in lymphocytes of group II subjects.

Antigens, Fungal↗

In vivo and in vitro cell-mediated responses in coccidioidomycosis. I. Immumologic responses of persons with primary, asymptomatic infections.

Chest roentgenograms of 58 children who were skin test positive to coccidioidin and resided in an area endemic for coccidioidomycosis revealed that 34 per cent had roentgenographic evidence of an inflammatory process, 14 per cent showed calcific densities, and 52 per cent showed no evidence of infection. The in vitro lymphocyte responses of children who had evidence of an inflammatory process (Group I) were compared with those of children who had calcific densities (Group II); those of children who were coccidioidin skin test negative and had normal chest roentgenograms (Group III); and those of patients who had active coccidioidomycosis (Group IV). The mean lymphocyte transformation responses (expressed as cpm times 10-(4)) of Groups I, II, III, and IV to a coccidioides antigen were 16.8, 19.5, 4.2, and 7.0, respectively. The mean migration inhibitory factor responses of these groups were 22.4, 20.0, 1.2, and 4.0 per cent, respectively. Thus, the over-all responses of children in Groups I and II were comparable to each other, whereas the responses of patients in Group IV were depressed to the extent that they were indistinguishable from those of coccidioidin skin test-negative donors in Group III. Follow-up chest roentgenograms taken 3 months after the immunologic assays were performed revealed that the one subject in Group I who had been nonresponsive in the lymphocyte assays had now stabilized his infection, as evidenced by calcifications. In contrast, the 2 subjects in Group I who had yet to stabilize their infection had exhibited strong in vitro lymphocyte responses. These findings suggest that primary, asymptomatic coccidioidomycosis is not associated with an immunologically nonresponsive state. However, patients with active, progressive coccidioidomycosis do have a depressed immunologic response to coccidioides antigens.

Adolescent↗

Immunoglobulin E antibody formation in response to homologous rabbit albumin heavily substituted with dinitrophenol: effect of adjuvant.

Although much progess has been made in the detection and characterization of homocytotropic antibodies, identification of the factors which control their synthesis remains to be determined. To assess the influence of different adjuvants on anti-dinitrophenol (DNP) immunoglobulin E (IgE) antibody responses, rabbits were immunized with adjuvant plus homologous albumin (HRA) heavily substituted with DNP (DNP30-HRA). This antigen in rabbits has a B cell-reactive determinant (DNP) and weak non-B cell-reactive determinants (new antigenic determinants) which sensitize rabbits for delayed-type hypersensitivity reactions to DNP30-HRA. It was postulated that the anti-DNP IgE response to DNP30-HRA could be regulated if the immunogenicity of the weak non-B cell-reactive determinants (new antigenic determinants) in DNP30-HRA could be manipulated by adjuvants and dosage. Complete Freund adjuvant and incomplete Freund adjuvant increased the immunogenicity of the new antigenic determinants in DNP30-HRA (10 mg) much more than did alum. However, equivalent primary anti-DNP IgE responses were made by all rabbits sensitized with this dose, regardless of the adjuvant used. Larger doses of DNP30-HRA (25 mg) in alum sensitized rabbits for strong delayed-type hypersensitivity reactions to DNP30-HRA and also elicited enhanced and persistent primary anti-DNP IgE responses. Enhanced but transient primary anti-DNP IgE responses were elicited by 25 mg of DNP30-HRA in incomplete Freund adjuvant. In contrast, no primary anti-DNP IgE responses were made to 25 mg of DNP30-HRA in complete Freund adjuvant. Regardless of the adjuvant or dosage used for primary immunization, no secondary anti-DNP IgE responses to DNP30-HRA were detected.

Adjuvants, Immunologic↗

Synergy of fluconazole with macrophages for antifungal activity against Candida albicans.

The possible between macrophages and fluconazole for antifungal activity against different isolates of C. albicans was studied. The susceptibility of C. albicans isolates to fluconazole (FCZ), when incubated in RPMI-1640 with 10% fetal bovine serum (FBS) and 10% fresh mouse serum (test medium, TM) was determined by using a quantitative culture methodology, Multiplication of isolate Sh27 was strongly inhibited by FCZ, even at 1.0 microgram/ml. However, FCZ even at 100 microgram/ml was not fungicidal. Resident murine peritoneal macrophages (MP) incubated for 48 h in RPMI-1640 + 10% FBS (tissue culture medium, TCM), then challenged with Sh27 in TM for 24 h, were fungistatic (20 +/ 9%, n = 4). Cultured macrophages synergized with FCZ (10 micrograms/ml) for fungicidal activity when co-cultured with sh27 in TM for 24 h (46 +/ 8%) and for 48 h (74 +/ 5%), n = 3. Macrophages and FCZ (10 micrograms/ml) could not synergize for significant killing of a less FCZ-sensitive C. albicans isolate 94-164. Multiplication of a FCZ-resistant isolate (94-20) was not inhibited by FCZ at 10 micrograms/ml TM; however, macrophages and FCZ (10 micrograms/ml) could synergize for fungistatic (64%), but not fungicidal, activity.

Animals↗

Isolation of a human serum protein that inhibits the growth of Cryptococcus neoformans.

Human serum at 5 to 10% (v/v) in tissue culture medium RPMI-1640, inhibits the growth of Cryptococcus neoformans by 80 to 93%. Serum fractionated on molecular sieve columns (Sephadex G-200) yielded an active protein fraction. This fraction at 100 micrograms protein/ml inhibited the growth of C. neoformans by 54%. When an active G-200 fraction was applied to a dye affinity column (Affi-Gel Blue) the fraction with inhibitory activity was bound by the column and was eluted with 1.4 M NaCl in 0.1 M phosphate buffer (pH 7.4). The bound fraction at 62.5 micrograms protein/ml inhibited C. neoformans growth by 82%. On native polyacrylamide gel electrophoresis (Nu-PAGE) the bound fraction migrated as a major and a minor band. Under the reducing conditions of sodium dodecyl sulfate (SDS)-PAGE the bound fraction yielded 4 prominent bands with MW ranging from 175 kDa to 45 kDa. Purification of the active Sephadex G-200 peak was achieved using an anion exchange column (DEAE-Sephacel). Protein eluted with 0.1 M NaCl had strong anticryptococcal activity (12.5 micrograms/ml, 79% inhibition), which in SDS-PAGE migrated as a single band with an approximate MW of 85 kDA. This protein appears important in natural host resistance to C. neoformans and polymorphisms or deficiencies may have epidemiologic and diagnostic relevance.

Antifungal Agents↗

Human defenses against Cryptococcus neoformans: an update.

Cryptococcus neoformans var. neoformans is an opportunistic fungal pathogen, especially in AIDS patients, and is found world-wide. On the other hand, Cryptococcus neoformans var. gatti (CN-g) is restricted to an association with two species of Eucalyptus trees. Alveolar macrophages (AM) constitute the first line of defense to Cryptococcus neoformans and offers some resistance. The inflammatory response to Cryptococcus neoformans with an influx of neutrophils and monocytes affords a second line of defense. Secretion of proinflammatory monokines by human AM is now being defined. The inflammatory phagocytes are efficient in killing Cryptococcus neoformans and offer strong resistance. T and B cell responses to infection, a third line of defense, results in production of lymphokines (IFNg, etc.) and specific antibodies. Enhancement of lymphocyte responses by IL-12 and IL-18 to Cryptococcus neoformans infection appears to be critical. Susceptibility of AIDS patients to Cryptococcus neoformans is associated with low CD4+ T cell counts and likely reduced efficacy of the second line of defense.

AIDS-Related Opportunistic Infections↗

Comparison of fluconazole and ketoconazole in experimental murine blastomycosis.

Fluconazole, a new oral triazole antifungal agent, was tested against Blastomyces dermatitidis in vitro and in a murine model (pulmonary challenge) and compared with ketoconazole, an oral imidazole known to be effective against this agent in mice and in humans. Although fluconazole appeared less active than ketoconazole in vitro, in experiments involving 3 weeks of treatment and 2 months of observation, fluconazole was greater than 10 times as potent (mg/kg) in vivo against blastomycosis (prolongation of life). In the model neither drug was curative at the doses and regimens used. A possible explanation for the efficacy of fluconazole in vivo is its favorable pharmacokinetic profile (i.e., prolonged serum concentrations that exceeded the MIC for the pathogen after oral administration). Dosages of 100 mg/(kg.d) were tolerated for 3 weeks without evident toxicity.

Animals↗