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Biomedical subjects

E Reiss

Publications and source records attributed to E Reiss.

At least 73 records · Page 4Linked to original sources
PubMed1984

Enzyme immunoassay detection of IgM to galactoxylomannan of Cryptococcus neoformans.

Antibodies against the major capsular polysaccharide of Cryptococcus neoformans, glucuronoxylomannan (GXM), and a minor secreted polysaccharide, galactoxylomannan (GalXM), were surveyed by indirect enzyme immunoassay (EIA) in patients with cryptococcosis, with other mycoses, and in normal controls. Measurement of IgG levels against GalXM revealed cross reactions in candidiasis patients that were reduced by adsorption with Candida albicans cell walls. Measurement of IgM levels were subject to fewer cross reactions. The combination of adsorption with C albicans cell walls and measurement of IgM detected antibodies in 12 of 55 cryptococcosis patients. An end point equal to or greater than a titer of 1/16 excluded reactions in normals and limited cross reactivity in candidiasis patients to below 7%. This test has potential diagnostic significance in cryptococcosis patients who show no evidence of cryptococcal antigen circulating in the cerebrospinal fluid or serum. Reactions in this IgM assay were not spuriously due to rheumatoid factor. The major capsular GXM was much less serologically active and was subject to cross reactions with agents of bacterial sepsis. The specificity of the GalXM is directed mainly by the mannose and to a lesser extent by galactosyl residues.

Antibodies, Anti-Idiotypic↗
PubMed1984

Analytical isoelectric focusing of secreted dermatophyte proteins applied to taxonomic differentiation of Microsporum and Trichophyton species (preliminary studies).

Culture filtrates were prepared from dermatophytes under standard conditions and adapted for analytical isoelectric focusing in thin layer polyacrylamide gels over the pH range 3.5-9.5. Dermatophytes grown in trypticase soy broth secreted a large number of proteins displaying a wide range of isoelectric points (pIs). Trichophyton megninii extracts contained a triplet of proteins focusing in the pH 8.0-8.5 range that were absent in taxonomically related T. kuryangei isolates. Single ascospore isolates and standard tester strains of Nannizzia otae (+) mating type were differentiated from the (-) mating type by proteins focusing at pH 6.5 and 8.4. These were markedly reduced in the (+) type. The isofocused pattern of Microsporum canis conformed closely to the (-) mating type of N. otae. The protein patterns of T. megninii and T. kuryangei were distinct from those obtained with M. canis and M. equinum because of an intense-staining broad protein band, pI 7.2, and three periodic acid-Schiff-positive glycoproteins focusing in the acidic range which were absent in the Microsporum species. A characteristic protein or doublet (pI 8.7) was present in the Microsporum species and absent in the Trichophyton species. Analytical isoelectric focusing is a potentially useful method to distinguish inter- and intra-species differences in the pattern of secreted dermatophyte proteins present in culture filtrates and in trichophytins. The information derived may be useful in the classification of species.

Culture Media↗
PubMed1983

Simultaneous determination of arabinitol and mannose by gas-liquid chromatography in experimental candidiasis.

A method is described for the simultaneous quantitation of D-arabinitol and D-mannose in serum by gas-liquid chromatography as an aid for the diagnosis of disseminated candidiasis. Both variables were observed as per-O-acetylated aldononitrile derivatives in each chromatographic run of sera from immunosuppressed rabbits experimentally infected with Candida albicans 3181A.

Animals↗
PubMed1982

Dissociation of mannan--serum complexes and detection of Candida albicans mannan by enzyme immunoassay variations.

Candida albicans mannan was added to normal human sera and the resulting complexes were dissociated by boiling (boil) with EDTA or by alkali treatment (bead method). The mannan released was detected by "sandwich" enzyme immunoassay (EIA) or by EIA inhibition. Each EIA took 2.3 h to perform. The total time for the boil-EIA combination was 2.7 h and for the bead-EIA, 3.8 h. The temperature favorable for antigen--antibody incubation was 4 degrees C. The sandwich EIAs were preferable to EIA inhibition because absorbance was directly proportional to mannan concentration, within-run variation was decreased, and accuracy was increased. The boil-sandwich EIA had the highest sensitivity in the 12.5 to 200 micrograms/L range.

Antigen-Antibody Complex↗
PubMed1981

A microsomal fraction of Cryptococcus neoformans induces lymphocyte blastogenesis in infected guinea pigs.

Differential centrifugation of a homogenate from a mechanically disrupted, acapsular isolate of Cryptococcus neoformans resulted in a 105,000 x g supernatant (105 K) and a microsomal fraction (MS), both of which were capable of eliciting specific delayed cutaneous hypersensitivity and in vitro blastogenesis in infected guinea pigs. Polyacrylamide gel electrophoresis revealed two major proteins in the MS and seven proteins in the 105 K fractions. Electron microscopy of the MS showed both membranes and ribosomes. In vitro lymphocyte blastogenesis elicited by 1 to 10 micrograms/ml of antigens was maximal after 4 days of incubation; the reacting populations were peripheral blood leukocytes (PBL) and peritoneal exudate cells (PEC). Spleen cells of infected animals were unresponsive to in vitro antigenic stimulation. A simplified schedule of priming animals was infection with a single dose of virulent cryptococci. Under these conditions 3 of 6 animals' PBL responded with stimulation ratios of 6.55, 21.1, 35.42 to the MS and 1.41, 9.33, 17.39 to the 105 K antigens at 1 microgram/ml. Four of six animals' PEC response were positive with stimulation ratios of 2.62, 2.72, 4.02 and 7.20 towards MS, and 2.62, 5.13, 5.71, 10.01 to the 105 K antigens at 1 microgram/ml. When small capsule and large capsule isolates were used for infection, the small capsule form was not isolated from the brain, in contrast to its isolation from 2 of 3 animals receiving large capsule forms. Two of three animals in each group responded with blastogenic indices more vigorous in the PBL, and the most potent antigen was MS. There was no obvious difference in lymphocyte reactivity between the two groups.

Animals↗
PubMed1981

Structural analysis of mannans from Candida albicans serotypes A and B and from Torulopsis glabrata by methylation gas chromatography mass spectrometry and exo-alpha-mannanase.

Mannans of Candida albicans serotypes A and B and of Torulopsis glabrata were subjected to methylation analysis and the resulting monosaccharides were converted to the peracetylaldononitrile derivatives and subsequently analyzed by gas chromatography mass spectrometry. Serotype A differed from B in having more 1 leads to 2 linked mannosyl residues (46.2 vs 37.1 mol%) indicating longer oligomannosyl sidechains; mannosyl branch points linked through C-1, C-3 and C-6 were detected for the first time in C. albicans mannans and were more abundant in serotype B (9.2 vs 5.3 mol%). T. glabrata mannan differed from that of C. albicans in having virtually no (1.6 mol%) unsubstituted sugars in the linear backbone and less 1 leads to 2 linked mannosyl residues (33.1 mol%) interpreted as shorter oligomannosyl sidechains. Model building of a repeating unit for the outer chain region of these mannans was prevented by the large amount of nonreducing terminal mannosyl residues, 23.0 mol% for C. albicans A, that probably arise from the inner core region. These mannans were exposed to exo-alpha-mannanase and the percentage of digestion, measured as reducing sugar released, was 33.5% for C. albicans B; 27.4% for T. glabrata, and C. albicans A was refractory (5.4% digested).

Candida↗
PubMed1981

Detection of antibodies and antigenemia in leukemic patients with candidiasis by enzyme-linked immunosorbent assay.

Standard tests and two enzyme-linked immunosorbent assays (ELISAs) were compared for detecting systemic candidiasis in 92 leukemic patients. Antibodies to Candida were detected by immunodiffusion (ID), latex agglutination (LA), and indirect ELISA; antigenemia was evaluated by indirect ELISA inhibition. In 48 patients without candidiasis (group 1), sera from 27% reacted in ID and 13% in LA tests; titers of antibody by ELISA occurred in all patients. In 34 patients without disseminated candidiasis (groups 2 and 3), Candida species were isolated; sera from 35% and 32% were positive in the ID and the LA test, respectively. In nine of 10 patients with disseminated candidiasis (group 4), LA and ID tests were negative. Seven patients in groups 1-3 without disseminated candidiasis were antigenemic (false-positive rate, 9%). Antigenemia was detected in seven of 10 patients with disseminated candidiasis; in the remaining three patients sera were drawn too early to be of diagnostic value. Thus, monitoring of immunosuppressed patients for mannan antigenemia is useful for the detection of disseminated candidiasis.

Adult↗
PubMed1980

Detection of Candida albicans mannan by immunodiffusion, counterimmunoelectrophoresis, and enzyme-linked immunoassay.

Anti-mannan was produced in rabbits after peptidoglucomannan in adjuvant was injected. The antiserum was used to detect mannan by immunodiffusion and counterimmunoelectrophoresis (CIE) in gel and by sandwich enzyme-linked immunosorbent assay (ELISA). The antiserum detected lower concentrations of mannan of serotype A than of serotype B. Except in CIE, the reactions were more pronounced at 4 degrees C than at higher temperatures. CIE detected 0.8 microgram/ml mannan A or 12.5 microgram/ml mannan B. Sandwich ELISA detected 3 ng/ml mannan A or 10(5) ng/ml mannan B. Mannan was not detected in the serum of patients or rabbits with candidiasis.

Animals↗
PubMed1980

Comparison by ELISA of serum anti-Candida albicans mannan IgG levels of a normal population and in diseased patients.

Titers of serum IgG with specificity for C. albicans mannan were assessed by enzyme-linked immunosorbent assay (ELISA) in a group of 640 normal persons. Substantial differences in titers were found when comparing individuals but not among groups divided by race, sex, or age. As a group, leukemics showed a pattern of IgG titers similar to that of the normal population. Sera from six patients with chronic mucocutaneous candidiasis showed that IgG levels were markedly variable in this disease. Anti-mannan IgG was not detected in normal rabbit serum but was found in serum from infected animals. The results indicate the necessity of serial sampling if serological methods, such as ELISA, are to be useful in aiding the diagnosis of invasive candidiasis.

Adolescent↗
PubMed1980

Concomitant but not causal association between surface charge and inhibition of phagocytosis by cryptococcal polysaccharide.

The mechanism by which capsular polysaccharides inhibit phagocytosis is not clearly understood. We investigated the association between a negative surface charge and inhibition of phagocytosis by the capsular polysaccharide of Cryptococcus neoformans. A two-polymer aqueous-phase system containing phosphate ions was used to assess surface charge. Opsonins such as normal bovine serum and normal human immunoglobulin G reduced the surface charge on non-encapsulated cryptococci and simultaneously enhanced phagocytosis. These same opsonins had no effect on phagocytosis or surface charge of encapsulated cryptococci. F (ab')(2) fragments of normal human immunoglobulin G neither enhanced phagocytosis nor altered the surface charge of non-encapsulated cryptococci. Addition of purified cryptococcal polysaccharide to non-encapsulated cells inhibited phagocytosis of the yeast and induced a strong negative charge at the yeast surface. Chemical modification to reduce the surface charge of either purified cryptococcal polysaccharide or intact encapsulated cryptococci produced a small loss of phagocytosis-inhibiting activity; however, all treated polysaccharide preparations retained a significant ability to inhibit phagocytosis of the yeast. These results indicated that the association between surface charge and inhibition of phagocytosis was largely circumstantial, and presence of a negative surface charge could not account for the powerful antiphagocytic action of cryptococcal polysaccharide.

Cell Membrane↗
PubMed1980

Metabolic consequences of oral administration of 24,25-dihydroxycholecalciferol to uremic dogs.

24,25-dihydroxycholecalciferol [24,25-(OH)(2)D(3)], once considered a relatively inert metabolite of vitamin D(3), has been recently recognized as a metabolically active product in some species. In previous studies, we have shown that infusion of 24,25(OH)(2)D(3) into the thyroid artery of normal dogs results in prompt and complete suppression of parathyroid hormone (PTH) secretion. In this study, we have examined the metabolic consequences of oral administration of this metabolite in dogs with experimentally induced renal hyperparathyroidism. Dogs with comparable degrees of renal insufficiency (glomerular filtration rate, 10-15 ml/min) were treated for 3 wk with daily doses of either 2 mug of 24,25(OH)(2)D(3) or 50% ethanol, the vehicle in which the metabolite was suspended. After a 6-wk recovery period, treatments were reversed: dogs who had previously served as controls received the metabolite while dogs previously treated with metabolite received the vehicle. Administration of 24,25(OH)(2)D(3) resulted in a 40-60% decrease of immunoreactive PTH. This was associated with a small (0.1-0.2 mg/dl) but unequivocal decrease of serum ionized calcium. Calcium balance, which was slightly negative under control conditions, became slightly but definitively positive on treatment with 24,25(OH)(2)D(3). All other parameters measured, including total serum calcium, magnesium, phosphorus, creatinine, electrolytes, phosphorus excretion, and phosphorus balance, remained unchanged. The data support the hypothesis that 24,25(OH)(2)D(3) not only decreases PTH secretion but also functions as an anabolic hormone in bone under the conditions of this experiment.

Administration, Oral↗
PubMed1979

Galactomannan antigenemia in invasive aspergillosis.

Galactomannan (GM) extracted from mycelia of Aspergillus fumigatus with cold dilute alkali reacted with antiserum specific for an antigen that circulated in invasive aspergillosis in rabbits and humans. The GM was purified by its affinity for concanavalin A and was separated from a nonantigenic glucan by gel permeation on Sephacryl S-200. The GM molecular weight of between 25,000 to 75,000 was smaller than the antigen present in infected rabbit serum which was retained by an ultrafiltration membrane that had a nominal molecular weight limit of 125,000. The ratio of galactose to mannose present in GM was 1:1.17. The serological activity of GM was stable to boiling but labile to 0.01 N HCl, implicating galactofuranose as an antigenic determinant. Analysis of purified GM by methylation-gas chromatography suggested a structure consisting of a 1 leads to 6-linked mannan backbone with oligogalactoside side chains 3 units long, terminating in galactofuranose. The presence of mannose as a side chain component was also inferred. Another antigen of A. fumigatus, which did not bind to concanavalin A, was isolated after tandem chromatography on diethylaminoethyl- and carboxymethyl-Sephadex and was identified as a galactan. The galactan inhibited the immune precipitation of GM was specific antiserum.

Animals↗