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J Cazin

Publications and source records attributed to J Cazin.

At least 19 recordsLinked to original sources
PubMed1993

Biotin and biotin analogs in human urine: biotin accounts for only half of the total.

In studies using avidin-binding assays to measure the urinary excretion of biotin, biotin is sometimes assumed to be equal to the detectable avidin-binding substances present. High performance liquid chromatography was used to separate avidin-binding substances in human urine, and the chromatographic fractions were assayed for avidin-binding substances (biotin and biotin analogs) by a sensitive, specific assay based on binding of biotin to [125I]avidin. In a study of ten normal adults, substantial amounts of avidin-binding substances other than biotin were detected, two of which were bisnorbiotin and biotin sulfoxide. These biotin analogs were initially identified by their chromatographic properties, and identities were confirmed by chemical conversion. The presence of avidin-binding substances in addition to biotin may have confounded previous measurements of the urinary excretion of biotin using avidin-binding assays. Because bioassay methods for biotin often use organisms for which one or more of these biotin analogs are growth factors, measurements of biotin in urine using some bioassay methods are likely to overestimate the concentrations of biotin.

Avidin↗
PubMed1989

Isolation, growth characteristics, and long-term storage of fungi cultivated by attine ants.

Seven pure-culture strains of fungi cultivated by attine ants (ant-garden fungi) were isolated from locally maintained leaf-cutting ant colonies. An ant-garden fungus strain obtained from an Atta cephalotes colony, when offered to ants of the colony from which the fungus was isolated, was accepted as their own. Young fungus cultures were harvested and incorporated into the fungus garden, and cultures of intermediate age were used to begin a new fungus garden; old cultures were simply harvested. To facilitate further research on this fungus, growth characteristics of the different isolates were studied under a variety of conditions. They grew better at 24 degrees C than at 30 degrees C, and growth did not occur at an incubation temperature of 37 degrees C. In a broth culture medium, growth was enhanced by aeration of the culture and by addition of yeast extract, olive oil, sesame oil, peanut oil, soybean oil, corn oil, sunflower oil, cottonseed oil, walnut oil, safflower oil, or mineral oil. Glycerol did not noticeably affect growth, but Tween 80 inhibited growth. These fungi were extremely sensitive to cycloheximide, growth being totally inhibited at cycloheximide concentrations ranging from 0.4 to 4.0 mug/ml. To date, the ant-garden fungus isolates have remained viable in long-term mineral oil-overlay storage cultures for up to 4 years.

Journal Article↗
PubMed1988

Production of streptavidin in a synthetic medium.

A simple, inexpensive procedure for producing streptavidin has been described. The biotin-binding protein was produced by growing Streptomyces avidinii in a synthetic liquid culture medium containing L-asparagine as the sole nitrogen source. With this procedure, extraneous proteinaceous substances inherently present in culture media prepared with yeast extract or with peptones were not present to interfere with isolation and purification of streptavidin. When harvested after 7-8 days of incubation, the culture fluid was relatively free of contaminating cell breakdown products. Maximal production of streptavidin (100-120 mg/l) was obtained in 8-10 day cultures. For some applications, the culture fluid can be used directly as a source of streptavidin. Under the same conditions used to grow S. avidinii, 11 other actinomycete strains and 134 eumycetes were found to lack the capacity to produce detectable amounts of an extracellular biotin-binding protein.

Bacterial Proteins↗
PubMed1988

Isolation and characterization of highly purified streptavidin obtained in a two-step purification procedure from Streptomyces avidinii grown in a synthetic medium.

A method is described for isolation of streptavidin from cultures of Streptomyces avidinii grown in a synthetic culture medium for 6-10 days. Streptavidin is precipitated directly from culture supernatant fluid using 80% ammonium sulfate, and the precipitate is dialyzed against water and centrifuged at 40,000 X g for 60 min. The absorbency coefficient at 280 nm of purified streptavidin was estimated to be 31.7142 +/- 0.1806 for a 1% solution. The protein appeared to be greater than 90% homogeneous by gel permeation chromatography and polyacrylamide gel electrophoresis. No biotin-binding molecules less than 70 kDa in size were detected at any step during the purification of streptavidin. Streptavidin was able to maintain a stable crosslink between two biotinylated molecules in a solid-phase assay. Streptavidin purified by this method was stable in 50% glycerol/water at -20 degrees C for more than 1 year. Lyophilization or iodination did not produce apparent damage to the protein.

Bacterial Proteins↗
PubMed1983

The comparative virulence of thermotolerant Mucorales species in mice.

The comparative virulence of thermotolerant Mucorales was determined for cortisone-treated and untreated Swiss mice by intravenous administration of spores. The measure of virulence was based on an LD50 value, calculated after the 30-day observation period. Of the known etiological agents of mucormycosis, Mucor meihei, M. pusillus, Rhizopus arrhizus, R. chinensis, R. cohnii, R. microsporus, R. oryzae, R. rhizopodiformis and Cunninghamella elegans were able to produce fatal infections in mice; whereas, Mucor alternans, M. ramosissimus and Syncephalastrum racemosum were avirulent at dosages of up to 10(5) spores. Of those thermotolerant species which have not been reported to cause mucormycosis in human beings, Radiomyces embreei, R. spectabilis, Rhizopus oligosporus and Thermomucor indicae-seudaticae were found to produce fatal infections in mice; whereas, an isolate of Mycotypha africana was avirulent. Cortisone treatment of mice was found to lower their resistance to infection at a given spore dosage as measured by ET50 values.

Animals↗
PubMed1983

Antigens of alternaria. I. Isolation and partial characterization of a basic peptide allergen.

A basic peptide allergen has been isolated from Alternaria extracts. Flat-bed gel preparative isoelectric focusing followed by dialysis and lyophilization allowed for concentration of substantial quantities of this heretofore unrecognized allergen. Rocket immunoelectrophoresis and autoradiography (using a 2 X concentrated, IgE serum fraction from Alternaria patient sera and 125I-anti human IgE), a RAST inhibition assay, and skin testing of Alternaria-sensitive patients were used to demonstrate the allergenicity of this fraction. The allergenicity of this protein was sufficient to give 50% RAST inhibition at a concentration of 100 micrograms/ml using standard RAST procedures. The immunoelectrophoresis autoradiography also indicated allergenicity. Skin tests indicated that over 90% of patients hypersensitive to Alternaria crude extracts were also hypersensitive to the basic allergen fraction.

Allergens↗
PubMed1983

Allergens of Alternaria: further characterization of a basic allergen fraction.

A basic allergen fraction isolated from Alternaria extracts by preparative flat-bed gel isoelectric focusing (as previously reported) was subjected to further characterization. The fraction was chromatographed on a Sephadex G-25 column and exhibited two major peaks, the first of which was allergenic and the second of which was nonallergenic but caused a precipitate to form when added to a mixture of sodium dodecyl sulfate (SDS) (1%) and trichloroacetic acid (5%). SDS-PAGE indicated that the allergen component of the basic fraction migrated at about the same rate as insulin (5.8 kdaltons). Both G-25 peaks were carbohydrate rich with a protein:carbohydrate ratio (by weight) of 1:4.5 and 1:5.8 for peak 1 and peak 2 respectively. Heat (100 degrees C for 10 min) and enzyme digestion (trypsin, alpha-chymotrypsin and pepsin) did not reduce the RAST inhibition values for peak 1 or the original basic fraction. The basic fraction did not bind human IgE specific for birch pollen indicating that the RAST inhibition and IgE (Alternaria specific) binding to radioimmunoelectrophoresis plates was not due to nonspecific binding of IgE. We conclude that the allergenicity of the basic fraction is due to a small molecule that is predominantly carbohydrate in nature and is a major allergen of Alternaria.

Allergens↗
PubMed1981

Comparative virulence of Absidia corymbifera strains in mice.

The comparative virulence of six different strains of Absidia corymbifera for cortisone-treated and untreated Swiss mice was determined. Spores of the six strains were inoculated into mice by the intravenous, intraperitoneal, and intranasal routes. All six strains were found to be virulent in cortisone-treated and untreated mice by the intravenous route. Up to a 16-fold difference in strain virulence was observed for cortisone-treated mice and up to a 10-fold difference for untreated mice. When spores were administered by the intraperitoneal route, 50% lethal dose values could be calculated only for the cortisone-treated mice, although a few deaths were seen in untreated mice challenged with 10(7) spores. Each of the six isolates of A. corymbifera, when administered in an intranasal dosage of 10(6) spores, produced death in some cortisone-treated mice. Studies made to determine the viability of spores produced by each strain revealed that germination was 90% or greater on Littman and YpSs agars at an incubation temperature of 40 degrees C in less than 12 h.

Animals↗
PubMed1980

Radiomyces a genus in the Mucorales pathogenic for mice.

The thermotolerant fungi Radiomyces spectabilis and R. embreei were tested for their ability to produce disease when injected intravenously into mice. All three strains of R. embreei tested were able to produce death in normal and cortisone-treated mice. Hyphal invasion was consistently observed in the kidneys of these animals, and involvement of the brain, heart and lungs was often seen at inoculum dosages of 10(4) and 10(5) spores. The single strain of R. spectabilis tested did not produce deaths; although cortisone-treated animals sometimes exhibited unilateral kidney involvement at necropsy.

Animals↗
PubMed1979

Humoral response to experimental petriellidiosis.

The humoral antibody response elicited by experimental infection with Petriellidium boydii and Monosporium apiospermum was studied. The variables of fungus strain, route of inoculation, and concentration of inoculum were examined. Viable spores from three strains of P. boydii and from three strains of M. apiospermum were inoculated intravenously into mice. Serum specimens were tested for antibody by the microtiter indirect hemagglutination assay. At 4 weeks after infection, the percentage of positive specimens among survivortically related either to the incidence of positive specimens or to the magnitude of the humoral response. Mice inoculated by either the subcutaneous or the intramuscular route with viable or killed spores from M. apiospermum 813 developed antibody. The mean antibody titer was greater in those animals receiving viable spores, and the magnitude of the humoral response was dose dependent. Animals inoculated intravenously with comparable inocula of the same strain developed similar levels of antibody. However, cultural studies of infected mice showed chronic infection only after intravenous inoculation. The kidney was the organ most consistently involved.

Animals↗
PubMed1977

Immune response to Cryptococcus neoformans soluble polysaccharide: immunological unresponsiveness.

Mice injected with 100 to 800 microgram of Cryptococcus neoformans soluble polysaccharide showed a reduced ability to produce antibody after a challenge immunization with polysaccharide emulsified in Freund incomplete adjuvant. These animals were considered immunologically unresponsive. Animals given an initial injection of 25 or 50 microgram of polysaccharide responded to a challenge immunization in the same manner as control animals. Reversion of unresponsive mice to antibody production without further antigenic stimulation did not occur during a 12-week experimental period. These animals exhibited a partial response to challenge immunization 8 weeks after induction of unresponsiveness, and they were fully responsive to challenge immunization at 12 weeks. Animals given a single dose of 0.1, 0.4, or 1.6 microgram of polysaccharide produced a marked anamnestic response after challenge immunization. Repeated injections of subimmunogenic doses of polysaccharide did not produce a marked anamnestic response and would induce unresponsiveness only when the cumulative dose reached 100 to 400 microgram of polysaccharide, suggesting that injected cryptococcal polysaccharide might be sequestered in some manner until an amount of antigen sufficient for induction of unresponsiveness is accumulated. This possibility was confirmed by immunofluorescence studies that revealed a long-term deposition of polysaccharide in the tubular epithelial cells of the kidney.

Animals↗
PubMed1976

Serological diagnosis of petriellidosis (allescheriosis). I. Isolation and characterization of soluble antigens from Allescheria boydu and Monosporium apiospermum.

Soluble antigens in culture filtrates of three strains of Petriellidium boydii and three strains of Monosporium apiospermum were examined. Antigens were separated from concentrated crude filtrates by anion-exchange chromatography. A single major peak (Antigen 1), constituting a significant proportion of the total recoverable carbohydrate, was the only product isolated from each of four chromatographed filtrates. Depending on the fungus strain, Antigen 1 consisted of 90--96% carbohydrate, 3-4% protein, and 2-4% nucleic acid. Antigen 1 was found to consist of a population of molecules with a heterogeneous molecular size when assayed by gel filtration chromatography; however, isolated fractions of Antigen 1 proved to be immunologically identical when examined by Ouchterlony immunodiffusion. In addition, Antigen 1 from each strain was immunologically identical to similar preparations of Antigen 1 from the other five fungus strains. Chromatography of culture filtrates from two strains of M. apiospermum revealed a second peak (Antigen 2), which was found to consist of 70% carbohydrate, 16% protein, and 4% nucleic acid. Although Antigen 2 contained four times as much protein as Antigen 1, the two preparations were immunologically identical by immunodiffusion tests. Ion-exchange chromatography proved to be a useful procedure for isolating antigens of P. boydii and M. apiospermum from culture filtrates.

Antigens, Fungal↗
PubMed1976

Production of extracellular ribonuclease by yeasts and yeastlike fungi, and its repression by orthophosphate in species of Cryptococcus and Tremella.

A strain of Cryptococcus laurentii and a haploid isolate of Tremella foliacea were shown to produce orthophosphate-repressible ribonuclease in liquid culture. Addition of as little as 1 mM K2HPO4, pH 7.0, completely repressed enzyme production by both fungi. The orthophosphate-repressible enzyme was not produced by other species of the two genera tested. These results, together with other findings, suggest a close phylogenetic relationship between Cryptococcus laurentii and Tremella foliacea. The ability of other yeasts and yeastlike fungi to hydrolyze ribonucleic acid in a solid test medium was assessed. Based on the limited number of organisms available for study, extracellular ribonuclease activity was found in species having close affinity to the Basidiomycetes and in yeasts classified in the ascomycetous genera, Endomycopsis, Hansenula, and Kluyveromyces. Other ascomycetous yeasts did not exhibit extracellular ribonuclease.

Ascomycota↗
PubMed1973

Pathogenicity of Allescheria boydii for mice.

Allescheria boydii and its imperfect state, Monosporium apiospermum, were studied to determine whether asexual or sexual strains might exhibit different pathogenic potentials for mice. Six different strains of the fungus were inoculated into mice by the intravenous, intracerebral, intraperitoneal, and intranasal routes. Cortisone-treated mice regularly developed infections after inoculation by any of the routes tested. Mice that had not been treated with cortisone were most susceptible to infection by the intravenous route and least susceptible to infection by the intranasal or intraperitoneal route; nevertheless, all animals that did not receive cortisone were considerably more resistant to infection by the fungus than were comparable groups of cortisone-treated animals. Pathogenicity of the fungus appears to be strain dependent and entirely unrelated to its sexual or asexual form. Studies made to determine accurate viable spore counts of the fungus revealed that the highest viable spore count was generally observed using Sabouraud dextrose agar or potato dextrose agar at an incubation temperature of 37 C for a period of 5 days.

Animals↗
PubMed1972

Immune response to Cryptococcus neoformans soluble polysaccharide. I. Serological assay for antigen and antibody.

Chromium chloride was used as a coupling agent for the conjugation of purified cryptococcal polysaccharide to sheep erythrocytes. Sensitized erythrocytes were used in a passive hemagglutination (PHA) assay for antibody to cryptococcal polysaccharide and a passive hemagglutination inhibition (PHI) assay for antigen. The PHA assay was more sensitive than complement fixation, agglutination, or precipitation tests for antibody. The PHI assay could detect submicrogram quantities of soluble polysaccharide. Antigen or antibody could be detected in serum or spinal fluid from seven of eight patients with cryptococcosis. Tests for antigen or antibody were negative with sera from patients with histoplasmosis, blastomycosis, coccidioidomycosis, aspergillosis, or allescheriosis. A low frequency (3%) of positive reactors for antibody was found among sera from normal persons and from persons with unrelated diseases; whereas, all tests for antigen were negative. The assay showed a high degree of sensitivity for immunoglobulins of the immunoglobulin M class; however, cryptococcal antibody of the immunoglobulin G class was also detected. The immunological specificity of the polysaccharide preparation was due to carbohydrate rather than to protein associated with the polysaccharide.

Animals↗
PubMed1971

Nonencapsulated Variant of Cryptococcus neoformans I. Virulence Studies and Characterization of Soluble Polysaccharide.

A weakly virulent nonencapsulated variant of Cryptococcus neoformans is described. The chemical structure and antigenicity of the soluble polysaccharides produced by the variant strain and a typical virulent strain were compared. The soluble polysaccharides produced by both strains were composed of the same constituent monosaccharides; however, the virulent strain produced a polysaccharide having a greater uronic acid content and a larger molecular size than that of the variant strain. Soluble polysaccharides from the two strains are not closely related immunologically. Soluble polysaccharide obtained from the virulent strain did not affect persistence of the variant strain in mice.

Journal Article↗