Biomedical subjects

W E Horner

Publications and source records attributed to W E Horner.

27 records · Page 2Linked to original sources

PubMed1989

Stability studies of Calvatia cyathiformis basidiospore allergens.

Calvatia cyathiformis allergens in unfractionated extract (crude), and in extract sequentially fractionated by gel filtration (GF) and hydrophobic interaction chromatography (HIC) were tested for stability. C. cyathiformis allergen sources (crude, GF, HIC) were sampled immediately (0 h), or incubated at 4, 24 or 37 degrees C and then sampled at 8, 24 or 96 h. Polyacrylamide gel-isoelectric focusing immunoprints revealed 3 allergen(s) groups, or bands (Bds) with respective pI of 3.6-4.6, 6.6 and 9.3. Only Bds 3.6-4.6 were stable at 37 degrees C. At 24 degrees C, Bds 3.6-4.6 persisted to 96 h, Bd 6.6 persisted 24 h, and Bd 9.3 waned in 8 h. At 4 degrees C all 3 allergens in HIC were stable for 8 and 24 h; Bd 9.3 was reduced at 96 h. All allergen activity was labile to low pH conditions except for Bds 3.6-4.6. Proteinase K degraded Bd 9.3 more rapidly than Bd 6.6. Immunoprint patterns corresponded to the stained gels and were consistent among different sources. Bd 9.3 is very labile, but reactive with 63% of sera tested. Since 10-15% of C. cyathiformis reactors bind IgE only to Bd 9.3, this is notable variability, and significant for diagnosis and treatment.

Allergens↗

PubMed1988

Identification and analysis of basidiospore allergens from puffballs.

Spore extracts from four common puffballs (Calvatia cyathiformis, Geaster saccatum, Pisolithus tinctorius, and Scleroderma areolatum) were fractionated by Sephadex G-75 gel filtration. Pooled fractions, analyzed by skin test or direct RAST, contained allergenic components over a molecular weight range of 10,500 to 20,000 daltons for all puffball spores studied except for S. areolatum (greater than 70,000 daltons). The Sephadex G-75 allergenic pool of C. cyathiformis was further fractionated by hydrophobic interaction chromatography. Fractions were successively eluted with 4 and 1 mol/L buffered saline solutions and water. The 1 mol/L fraction contained maximal allergenic activity as determined by RAST-inhibition studies. At least 15 Coomassie blue staining bands were identified after isoelectrofocusing, of which 7 were shown by immunoprinting to bind IgE from a serum pool of five patients with allergy. Our results demonstrate that a combination of gel filtration, hydrophobic interaction chromatography, RAST-inhibition, and immunoprinting studies can be used to fractionate, characterize, and standardize spore allergen extracts of puffballs for diagnostic and therapeutic purpose.

Allergens↗

PubMed1988

Characterization of allergens from spores of the oyster mushroom, Pleurotus ostreatus.

Crude extracts of Pleurotus ostreatus spores obtained from a single local source were fractionated by gel filtration to resolve the allergenic components. The fraction pool corresponding to 10.5 to 25 kd molecular weight contained allergenic activity as demonstrated by both RAST and skin testing. Similar results were obtained with extracts from spores that originated in four other areas and with extracts prepared from P. sajor-caju spores obtained from commercially produced caps. The RAST-active fraction was further separated by hydrophobic interaction chromatography (HIC). HIC fraction pools were assayed for allergen(s) by RAST inhibition and immunoblotting of isoelectric focused polyacrylamide gels. RAST-inhibition data indicated that the allergen(s) was reversibly bound to the HIC column, eluting with 2, 1, and 0.15 mol/L of buffered salt solutions. After electrofocusing, these fractions yielded 15, 12, and 11 Coomassie brilliant blue-staining bands, respectively. IgE binding occurred with 7, 8, and 6 of these bands, as revealed by radiostaining of the immunoblots. These procedures help identify P. ostreatus spore allergens and allow a greater degree of standardization in the preparation of allergen extracts from basidiospores for use in diagnosis and therapy of fungal allergy.

Allergens↗

PubMed1988

Basidiospore allergens: analysis of Coprinus quadrifidus spore, cap, and stalk extracts.

Atopic individuals with symptoms of respiratory allergy have been shown to have IgE-mediated reactions to spores from the basidiomycete fungi. Because our earlier studies suggested that parts of the fungus other than spores may contain allergens, the current study was performed. Extracts of Coprinus quadrifidus spores, caps, and stalks were prepared and fractionated by gel filtration column chromatography on Sephadex G-75. Analysis of column fractions of each separation by ultraviolet absorption demonstrated at least three peaks of absorbency in spore, cap, and stalk extracts. Pooled column fractions were analysed by direct radio-allergosorbent test (RAST) using pooled sera from C. quadrifidus skin-test positive subjects. Enhanced allergenic activity was present in the same portion of the column eluate for cap, spore, and stalk fractionations, corresponding to a molecular weight of approximately 10.5-25 kD. Pools with allergenic activity were used to test volunteers by skin prick and RAST. Skin test and RAST activities were similar for each of the three Coprinus extracts, with stalk being the most potent. Evidence of common allergenic epitopes was demonstrated by inhibition of spore RAST by spore, cap, and stalk extracts. These results suggest that C. quadrifidus cap and stalk extracts contain allergens similar to those in spores extract and may provide useful sources of allergen for further study.

Agaricales↗

PubMedDate not supplied

Identification of the allergen Psi c 2 from the basidiomycete Psilocybe cubensis as a fungal cyclophilin.

Basidiospores are a prevalent and frequent cause of respiratory allergies, yet their allergens remain poorly defined; thus, we have attempted a molecular characterization of representative basidiomycete allergens. A Psilocybe cubensis mycelial cDNA library was immunoscreened with patient serum. A clone was isolated that expressed a 23-kD recombinant allergen as a fusion protein and inhibited a 16-kD band (Psi c 2) in immunoprints of P. cubenis extract, indicating antigenic identity. Sequence (cDNA) analysis of the clone indicates homology with cyclophilin and the deduced amino acid sequence of Psi c 2 showed 78% identity and 4% similarity with the amino acid sequence of Schizosaccharomyces pombe cyclophilin. This recombinant allergen is a useful model for epitope analysis of basidiospore allergens and fungal allergen cross-reactivity, and may provide an improved reagent for basidiospore allergy diagnosis and treatment.

Agaricales↗

PubMedDate not supplied

Health risks from exposure to metals in household dusts.

The levels of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), mercury (Hg), and nickel (Ni) were determined in a total of 315 indoor and outdoor dust samples collected from 53 households in Louisiana. Inductively coupled plasma analysis revealed that in many samples, the metal content exceeded the United States Environmental Protection Agency (EPA) Risk-Based Concentration (RBC) guidelines. For example, the number of dust samples above the EPA-RBC included 64 for Cd, 52 for Hg, 43 for As, 4 for Fe, 4 for Cu, 3 for Cr, and 2 for Ni. One-hundred fifty-two samples exceeded the street-dust level for Pb published by the U.S. Agency for Toxic Substances and Disease Registry. The results of this study indicate that exposure to indoor and/or outdoor dust presents a potential health risk for Louisiana residents.

Air Pollutants↗

PubMedDate not supplied

Potential health risks from indoor exposure to chlorpyrifos (O,O-diethyl O-[3,5,6-trichloro-2-pyridyl] phosphorothioate).

A four-season, indoor air quality survey was conducted in Southern Louisiana to determine the indoor air levels of the pesticide chlorpyrifos. Gas chromatographic analysis of 213 air samples collected from 53 houses revealed levels of chlorpyrifos ranging from non-detected to 2.13 micrograms/m3. Using the Florida-Pinella exposure guideline (24-hr exposure to chlorpyrifos at 0.48 microgram/m3), it was noted that 14% of the samples exceeded this guideline. The exposure of occupants to the indoor air concentrations of the pesticide, however, were below either the irritation or the odor thresholds, and effects on acute and chronic health responses remains uncertain.

Air Pollution, Indoor↗

PubMedDate not supplied

Protease activity in cockroach and basidiomycete allergen extracts.

Inherent proteolytic activity was estimated in cockroach and basidiomycete extracts by quantifying acid soluble peptides that were released by incubating extracts with 1% bovine serum albumin as measured by Lowry (Sigma). Reference proteases released 740 (Proteinase K, 0.1 U), 248 (Trypsin, 1.0 U), and 533 micrograms/ml (Pronase, 0.5 U) of soluble peptides. American whole body cockroach extract (0.1 mg dry weight) released 330 micrograms/ml of soluble peptides, representing 13 trypsin equivalent units (TEU)/mg. Extracts from spores of the mushroom Pleurotus ostreatus released 230 micrograms/ml (0.9 TEU/mg) and Pleurotus cap extract released 112 micrograms/ml (0.5 TEU/mg). Mycelium of Pleurotus and the mushroom Psilocybe cubensis and spores of Psilocybe and the puffball Calvatia cyathiformis showed negligible amounts of proteolytic activity. The protease inhibitor phenylmethylsulfonyl flouride reduced the proteolytic activity of American whole body cockroach extract by 80% (@1 mM) and the inhibitor ethylene diaminetetraacetic acid inhibited the proteolytic activity of Pleurotus spores by 95% (@1 mM). Loss of allergen activity as determined by RAST inhibition and immunoprinting correlated with protease activity. Thus, in the preparation and handling of allergen extracts, one should employ conditions that minimize proteolysis.

Agaricales↗

PubMedDate not supplied

Potential health risks from exposure to indoor formaldehyde.

An indoor air quality survey was conducted in Southern Louisiana to determine levels of airborne formaldehyde. Gas chromatography analyses of 419 air samples collected from 53 houses revealed levels of formaldehyde ranging from non-detectable to 6.60 mg/m3. Seventy four percent (312/419) of the samples had detectable amounts of airborne formaldehyde. Of the 312 positive samples, approximately 60% exceeded the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) guideline of 0.123 mg/m3. The highest number of samples exceeding the formaldehyde benchmark were collected in winter. It would appear that in some Southern Louisiana houses, a high level of formaldehyde could serve as a potential upper respiratory irritant.

Air Pollution, Indoor↗