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Biomedical subjects

S B Lehrer

Publications and source records attributed to S B Lehrer.

At least 19 recordsLinked to original sources
PubMed1995

Identification of important allergens in German cockroach extracts by sodium dodecylsulfate-polyacrylamide gel electrophoresis and western blot analysis.

BACKGROUND: Despite recent advances in the purification and characterization of cockroach allergens, identification of clinically important allergens and their source have not been completely elucidated. This study investigated the allergen content of German cockroach (Blattella germanica) whole body (GWBE) and fecal (GFE) extracts. METHODS: Sera from 37 subjects with asthma, with positive skin test results to cockroach, were used for RAST and Western blot (after sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE] under reducing conditions); this serum panel is the largest used to date for cockroach allergen analysis. RESULTS: RAST reactivity to GWBE and GFE were highly correlated (r = 0.882, p < 0.001). SDS-PAGE and Western blotting showed that GWBE and GFE had similar patterns of IgE binding. Furthermore, Western blot inhibition investigations revealed that either GWBE or GFE could almost completely inhibit the reactivity of the other extract, SDS-PAGE and Western blotting demonstrated in both extracts numerous bands that displayed a high prevalence of IgE binding. Protein bands at 67, 50, 45, and 36 kd bound more than 50%, and the band at 60 kd bound approximately 80% of the sera tested. CONCLUSIONS: In summary, this investigation identified German cockroach allergens, established their relative importance by prevalence of reactivity to a large serum panel, and demonstrated that cockroach feces possess significant allergenic activity. Five allergens identified demonstrated reactivity with up to 50% to 80% of the 37 subjects' sera tested.

Allergens↗
PubMed1995

Occupational IgE-mediated sensitization and asthma caused by clam and shrimp.

BACKGROUND: To confirm occupational asthma caused by clam and shrimp in a food company worker, the following investigation was planned in 60 other exposed workers (56 participants). METHODS: Before the production period of clam and shrimp, a medical and occupational questionnaire was carried out and skin and RAST testing were done with common inhalants and clam, shrimp, crab, and lobster extracts. During the production period, environmental monitoring was performed with personal and general samplers; inhalation testing with methacholine was proposed to subjects with immediate skin reactivity to clam, shrimp, or both. After the production period, all subjects with an immediate skin reactivity to clam, shrimp, or both and either a history of rhinoconjunctivitis, asthma, or bronchial hyperresponsiveness were seen by a specialist. RESULTS: Including the index case in whom occupational asthma to clam and shrimp had been confirmed, four (7%) subjects had a history of rhinoconjunctivitis and two (4%) had a history of asthma during the period of clam production, whereas three (5%) subjects had rhinoconjunctivitis and two (4%) had asthma during the shrimp production. Three (5%) subjects had immediate skin reactivity to clam, and nine (16%) subjects to shrimp. Four (7%) subjects had increased specific IgE antibodies (RAST binding > or = 3%) to clam and eight (14%) to shrimp. Significant associations were found between immunologic reactivity to clam and shrimp on the one hand and to crab and lobster on the other. Environmental monitoring demonstrated clam and shrimp on the air sampling filters. Occupational asthma caused by clam was confirmed by specific inhalation challenges in one subject in addition to the index case. These two subjects had skin reactivity and increased specific IgE antibodies to clam, shrimp, or both. CONCLUSION: By including the initial subject, the prevalence of immediate sensitization is 5% to 7% to clam and 14% to 16% to shrimp. Two (4%) subjects had occupational asthma caused by clam, and one (2%) had occupational asthma caused by shrimp.

Adult↗
PubMed1995

Fungal allergens.

Airborne fungal spores occur widely and often in far greater concentrations than pollen grains. Immunoglobulin E-specific antigens (allergens) on airborne fungal spores induce type I hypersensitivity (allergic) respiratory reactions in sensitized atopic subjects, causing rhinitis and/or asthma. The prevalence of respiratory allergy to fungi is imprecisely known but is estimated at 20 to 30% of atopic (allergy-predisposed) individuals or up to 6% of the general population. Diagnosis and immunotherapy of allergy to fungi require well-characterized or standardized extracts that contain the relevant allergen(s) of the appropriate fungus. Production of standardized extracts is difficult since fungal extracts are complex mixtures and a variety of fungi are allergenic. Thus, the currently available extracts are largely nonstandardized, even uncharacterized, crude extracts. Recent significant progress in isolating and characterizing relevant fungal allergens is summarized in the present review. Particularly, some allergens from the genera Alternaria, Aspergillus, and Cladosporium are now thoroughly characterized, and allergens from several other genera, including some basidiomycetes, have also been purified. The availability of these extracts will facilitate definitive studies of fungal allergy prevalence and immunotherapy efficacy as well as enhance both the diagnosis and therapy of fungal allergy.

Antigens, Fungal↗
PubMed1994

[Current aspects of fungal spores allergy].

In industrialized countries the prevalence of allergic inhalant diseases is some 15-20%. More than 10% of these individuals are sensitized to fungal allergens. Many fungal spores are less than 10 microns in size, which permits penetration into the smaller airways of the lung. Bronchial provocation tests have demonstrated that fungal spores and spore extracts can cause both an early and a late phase reaction in sensitive subjects. Over 80 genera of fungi have been associated with symptoms of respiratory tract allergy. Ascomycetes, basidiomycetes and zygomycetes are the major fungal groups that contain genera known to induce and elicit allergic reactions. These groups contribute most of the spores found in air. Although ascomycetes include the greatest number of any fungal group, only a few species, such as Aspergillus fumigatus, Alternaria alternata and Cladosporium herbarum, have been investigated in a scientific manner. In recent years spores of basidiomycetes have been tested for allergenicity and some species have been determined to be allergenic, such as Calvatia cyathiformis, Ganoderma applanatum, Pleurotus ostreatus, or Psilocybe cubensis. Compared to pollen-related allergies, diagnosis of fungal allergy is often difficult. Provocative challenge with specific fungal antigens can provide a definitive diagnosis. To date, only three controlled immunotherapy trials with standardized extracts of A. alternata and C. herbarum have shown clinical efficacy. In spite of these studies, immunotherapy with fungal antigens requires further investigations. Thus, the indication for immunotherapy with fungal extracts must be judged by an experienced allergist. Apart from pharmacological management, avoiding or minimizing exposure is the front-line measure.

Allergens↗
PubMed1994

Prevalence of basidiomycete allergy in the USA and Europe and its relationship to allergic respiratory symptoms.

A total of 701 adults living in the USA or Western Europe who had symptoms of allergic respiratory disease were skin prick tested with extracts prepared from eight basidiomycetes species and four Fungi Imperfecti species. In these subjects, the presence of asthma, rhinitis, or both was determined by questionnaire. Overall, 178/701 (25.4%) of the participants reacted to at least one basidiomycete extract. There was no difference in the prevalence of reactivity detected in the USA and Europe (P < 0.005); however, the prevalence of reactors in individual centers from both areas varied significantly. Psilocybe cubensis was the most potent allergen source in both the USA (12.3% reacted) and Europe (16.0%). Pleurotus ostreatus was second overall (10.6%) and in the USA (10.7%), and third in Europe (10.3%). Pisolithus tinctorius and Coprinus quadrifidus produced the least potent allergens, with only 5.4% of the population reacting. There was a significant relationship (P < 0.005) between basidiospore reactivity and the presence of atopy, asthma, and asthma and rhinitis. Basidiospore reactivity was not associated with the presence of rhinitis alone (P = 0.312). These results suggest that basidiomycetes are important sources of aeroallergens in geographically disparate regions and may be particularly important in patients with asthma.

Adult↗
PubMed1994

Identification of the major brown shrimp (Penaeus aztecus) allergen as the muscle protein tropomyosin.

Shrimp, a major seafood allergen, was investigated as a model food allergen. Extracts from both shrimp (Penaeus aztecus) meat and cooking fluid contain a substantial and similar amount of allergenic activity. A 36-kD allergen, demonstrated in both extracts by SDS-PAGE/Western blot analysis, reacted with 28/34 (82%) sera from shrimp-sensitive, skin test and RAST-positive, individuals. This allergen, named Pen a I, was isolated by SDS-PAGE; its amino acid composition was rich in aspartic and glutamic acids. A 21-residue peptide, obtained from endoproteinase Lys-C digested Pen a I by high-performance liquid chromatography, demonstrated significant homology (60-87%) with the muscle protein tropomyosin from various species and origins. The greatest homology (87%) was noted with tropomyosin of the fruit fly (Drosophila melanogaster) reflecting the phylogenic relationship between these two arthropods. These studies demonstrate that tropomyosin is the major shrimp allergen. Although the amino acid sequence of this shrimp muscle protein shares considerable homology with tropomyosins of other species including man, significant differences remain in allergenic activity.

Allergens↗
PubMed1994

Compliance and acceptance problems with standardized extracts.

In summary, there are a number of segments of the allergy community that are affected by compliance and acceptance of allergen standardization: regulators, allergen products manufacturers, allergists and allergy patients. To maximize compliance and acceptance of new products, these different groups must be considered when making decisions that impact on standardization and utilization of allergens. In closing it is essential that the following issues are addressed: Units--The number of different units currently used in the same extracts during the transition and the different units used throughout the world are particularly troublesome, both for physicians and patients that they treat. Uniform units or at least a formula to calibrate different units to an international system will go a long way in enhancing the compliance and acceptance of standardized products among those who produce them, use them and are treated by them. Cost--Cost of standardization continues to be a concern. The good news is that the new standardized extracts probably will not cost that much more than the old unstandardized extracts. However, implementation of new extracts can be expensive and we need to find ways in which we can minimize such costs to the allergy patients. Support is needed to continue allergen characterization. We need to encourage traditional sources of funds such as the NIH and manufacturers to continue to provide support for the allergen characterization and the standardization process. Commitment--Is the allergy community really committed to allergen standardization? Are regulators committed to provide the resources to develop standardized extracts? Does the allergist want to use standardized extracts? Do allergy sufferers really want standardized extracts in their treatment?(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗
PubMed1993

Allergic reactions to fish.

A wide variety of fish are known to induce allergic reactions following ingestion or inhalation of vapors by sensitized individuals. Although the exact prevalence of fish sensitivity is not known, fish are among the most important food allergens; and as consumption of fish increases, rates of sensitization are expected to increase. Diagnosis of fish allergy is aided by clinical history, skin prick testing, and in vitro assays; however, double-blind placebo-controlled food challenges are the most reliable method to confirm fish allergy and to identify putative species. It appears from RAST inhibition and SDS-PAGE/Western blot studies that the current policy of recommending that fish-sensitive individuals avoid all species of fish should be reevaluated. The major allergen in codfish (Gad cI) is one of the most extensively studied of all allergens. It is a calcium-chelating protein, with a mol wt of 12,328 kDa and an isoelectric point of 4.75. As an allergen, Gad cI is very stable and its allergenic activity appears to be dependent on amino acid sequence. Crossreactivity among some fish species may be the result of common structures within related proteins.

Allergens↗
PubMed1993

Basidiospore allergen release: elution from intact spores.

BACKGROUND: We sought to test the hypothesis that allergens are readily released by intact basidiospores in vitro and that different species release allergens in different patterns that are related to spore wall structure. METHODS: To assess basidiospore allergen releasability, basidiospore allergens were extracted from disrupted spores and eluted from intact spores, and the allergenic potency of the extracts and eluates was compared in Calvatia cyathiformis, Psilocybe cubensis, Lentinus edodes, and Pleurotus ostreatus. RESULTS: There was a significant species difference; on the basis of dry weight, the yield of extract and eluates from P1. ostreatus greatly exceeded the yield from C. cyathiformis extract and eluates. As measured by RAST inhibition, the allergenic potency of P1. ostreatus and L. edodes spore eluates reached the potency of disrupted spore extract in less than 4 hours. Allergen potency of Ps. cubensis and C. cyathiformis eluate approached the potency of disrupted spore extract only after 8 and 24 hours. Allergen staining intensity in sodium dodecyl sulfate polyacrylamide gel electrophoresis IgE immunoblot correlated with RAST activity. C. cyathiformis and Ps. cubensis spores have thick walls, whereas P1. ostreatus and L. edodes spore walls are thin and hyaline (nonpigmented). Thus spore allergen release may relate to spore wall characteristics. CONCLUSIONS: These studies indicate that intact basidiospores of all four species release allergens, but the release patterns differ by species, and these differences may be clinically significant.

Allergens↗
PubMed1993

Basidiomycete allergens: comparison of three Ganoderma species.

High atmospheric concentrations of basidiospores occur in various parts of the world. Ganoderma basidiospores are distinctive, easily identifiable in aeroallergen surveys, and widely abundant. Previous studies showed that Ganoderma basidiospores caused respiratory allergies. Thus, we investigated various extracts (spore, cap, and/or mycelial) of G. meredithae, G. lucidum, and G. applanatum for allergen components. Analyses included radioallergosorbent test (RAST) inhibition and IgE blots from isoelectric focusing (IEF) and SDS-PAGE. RAST inhibition with spores and caps of G. meredithae and G. lucidum showed that spores inhibited caps better than caps inhibited spores. Species differences were minor. Coomassie blue (CB) staining of IEF gels detected at least 23 protein bands (pI 3.6-6.6) in caps of G. meredithae and G. lucidum. G. meredithae spore extracts contained 17 of these (pI 3.6-5.0, 6.6). Spores and caps of G. meredithae contained 13 and 11 allergen bands, respectively, on IEF blots. SDS-PAGE of G. meredithae spore and cap showed one and four bands, respectively, by CB staining, but IgE blots showed 13 bands in cap and 17 in spore. Culture mycelia of G. lucidum and G. applanatum attained significant and essentially constant RAST activity by day 4. Activity was also present in culture supernatant by day 4. Blots of mycelium and supernatant detected a single allergen in day-8 mycelia and subsequently six allergen bands in day-16 mycelia and eight in day-16 supernatant (one appeared as a doublet). These data show that Ganoderma extracts contain a complex mixture of allergens. Differences among species were minor; spores and mycelia are apparently better sources of allergens than caps.

Allergens↗
PubMed1993

Identification of Psilocybe cubensis spore allergens by immunoprinting.

Previous studies established that Psilocybe cubensis contains potent allergens, and that a significant percentage of atopic subjects were sensitized to P. cubensis spores. The objective of this study was to identify P. cubensis spore allergens using isoelectric focusing (IEF) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) immunoprinting. Coomassie blue staining of IEF gels detected approximately 20 bands between pI 3.6 and 9.3. Immunoprints obtained with 15 P. cubensis skin test- and RAST-positive sera revealed 13 IgE-binding bands; the most reactive were at pI 5.0 (80%), 5.6 (87%), 8.7 (80%) and 9.3 (100%). SDS-PAGE resolved 27 proteins ranging from about 13 to 112 kD. SDS-PAGE immunoprints conducted with 11 skin test- and RAST-positive sera demonstrated 18 IgE-binding bands; most sera reacted to 16 (82%), 35 (100%) and 76 kD (91%) allergens. Both electrophoretic procedures demonstrated a single allergen (at pI 9.3 and 35 kD) that reacted with all sera tested. This study corroborates the allergenic significance of P. cubensis spores and identifies the allergens of greatest importance.

Allergens↗
PubMed1992

Passive cigarette smoke-challenge studies: increase in bronchial hyperreactivity.

Degree and duration of bronchial hyperreactivity (BHR) after environmental tobacco smoke (ETS) inhalation was assessed in 31 smoke-sensitive subjects with asthma who exhibited lower airway symptoms on ETS exposure (group I) and 39 smoke-sensitive subjects without asthma who manifested only upper airway symptoms on cigarette-smoke exposure (group II). Subjects were challenged with ETS for 4 hours in a static-test chamber. The atmosphere was continuously monitored for airborne particulate levels (800 cpm), total suspended particulates (1266 +/- 283 micrograms/m3), and airborne nicotine levels (226 +/- 49 micrograms/m2). Methacholine challenges were performed before and serially after cigarette-smoke exposure, and the provocative dose causing a 20% fall in FEV1 was determined. Five of the 31 smoke-sensitive subjects with asthma and none of the smoke-sensitive subjects without asthma reacted to cigarette-smoke challenge (greater than or equal to 20% fall from baseline FEV1). Thirty-two percent (10/31) of the subjects with asthma demonstrated increased BHR at 6 hours, 29% (9/31) at 24 hours, and 13% (4/31) up to day 14 after ETS challenge. Of the subjects without asthma, 18% (7/39) demonstrated increased BHR at 6 hours, 10% (4/39) at 24 hours, and 8% (3/39) at 3 weeks. These studies demonstrated an increase in BHR after cigarette-smoke challenge in a number of study subjects (although they were clinically asymptomatic) and suggest that prolonged subclinical airway inflammation can occur in the absence of demonstrable change in airway caliber on exposure to ETS.

Adolescent↗
PubMed1992

Effects of a GnRH agonist on fertility following administration to prepubertal male and female rats.

Leuprolide, a GnRH agonist, was administered daily to male and female rats for 90 days. Animals were sexually immature (25 days old) at the outset. Dosages were 20 and 200 micrograms/kg/day. Five males and five females were euthanized on Day 91. Sex organs were weighed and evaluated for histopathologic changes. These procedures were repeated 140 days later. Following a recovery period lasting 45 days (onset of normal-appearing estrous cycles) in females and 140 days (two spermatogenic cycles) in males, the fertility of these rats was assessed by mating with untreated animals. Treated males gained less weight while treated females gained more weight than controls. Weights of primary and secondary sex organs were reduced below control, but returned to normal following 140 days of recovery. Treated males were fertile and produced normal litters. Reproductive performance of low-dosage (20 micrograms/kg/day) females was normal 45 days after treatment cessation, but half of the high-dosage (200 micrograms/kg/day) females failed to become pregnant. However, reproductive performance of this group compared well with control performance after an additional 6 weeks of recovery. Atrophic changes were noted in male and female sex organs. Following 140 days of recovery, ovaries, uterus, vagina, prostate, and seminal vesicle were normal. Although testes and epididymides showed partial recovery at this time, multifocal or segmental atrophy and mineralization were noted in portions of some seminiferous tubules.

Animals↗
PubMed1992

Assessment of multiple markers of environmental tobacco smoke (ETS) in controlled, steady-state atmospheres in a dynamic test chamber.

Controlled test atmospheres of sidestream and mixed mainstream/sidestream tobacco smoke were produced in a dynamic test chamber of 16.9 m3 volume. University of Kentucky 1R4F research cigarettes were automatically smoked by a Borgwaldt smoking machine. Different target levels of smoke were attained by varying the number of cigarettes being smoked (one or two cigarettes continuously) and dilution airflow through the chamber (1.6 to 7.4 m3/min). For each level, a "smoke index" was calculated as the number of cigarettes being smoked divided by the dilution flow rate. Ultraviolet light-absorbing particulate matter (UVPM); aerosol counts and size distribution; and concentrations of CO, NO2, NH3, formaldehyde, acetaldehyde, acrolein, and nicotine were determined in the test atmospheres and background dilution air. Parameters exhibiting the highest correlations with smoke index (r2 > 0.98) included UVPM, aerosol counts, formaldehyde, and acetaldehyde. The other parameters were also highly correlated with r2 > 0.9 in each case. Differences in concentration for sidestream and mixed mainstream/sidestream atmospheres were statistically significant for acetaldehyde, formaldehyde, and CO; in each case the level was higher in mixed mainstream/sidestream smoke. These results demonstrate the utility of employing multiple markers for assessment of environmental tobacco smoke levels and for dichotomizing the contributions of sidestream and mainstream smoke to these levels. The generation factors developed in this work can be used for estimating required ventilation rates for attainment of target air quality conditions in smoking rooms.

Air Pollutants↗
PubMed1992

Chronological assessment of asbestos exposure on cell composition in murine lung.

To elucidate immune pathogenic mechanisms in asbestosis, lung and spleen lymphoid cell populations were analyzed at defined time intervals (1, 2, 3, 6, and 12 weeks during exposure and 4, 24, and 48 weeks post-exposure) in asbestos-exposed and unexposed (control) mice. Polymorphonuclear leukocytes and macrophages were increased in the lung tissue histologic sections of asbestos-exposed mice compared to controls. No consistent changes were observed in percentages of lung or spleen helper, suppressor, or total lymphocyte populations after asbestos exposure. The numbers of B cells (identified by anti-IgG) in minced lung preparations of asbestos-exposed animals were increased after 12 weeks of exposure. There also was an increase in IgG production in asbestos-exposed mice after 12 weeks exposure and at 4 weeks post-exposure with a return to near baseline levels 24 and 48 weeks after initial exposure. Collectively, these studies demonstrate stimulatory effects of inhaled asbestos fibers on B cells and IgG production after 12 weeks of continuous inhalation of asbestos fibers in a dust generation chamber.

Animals↗