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Biomedical subjects

H Baer

Publications and source records attributed to H Baer.

At least 91 records · Page 5Linked to original sources
PubMed1987

The role of specific IgE and beta-propiolactone in reactions resulting from booster doses of human diploid cell rabies vaccine.

Reactions after booster injections of human diploid cell rabies vaccine (HDCV) were investigated to determine the possibility of IgE-type antibody involvement. Although normal manufacture of HDCV involves the inactivation of the virus with beta-propiolactone (BPL), the effect of BPL on nonviral vaccine components, such as host cell components or stabilizing proteins, may be typical of the haptenic action of small molecular weight chemicals. Specific IgE to commercial HDCV preparations, BPL-treated preparations of noninfected host MRC5 cell sonicate (BPL-MRC5), and a human albumin (HA) (BPL-HA) used as a stabilizing agent were detected in sera from five individuals who reported reactions after booster doses of HDCV. However, these patients had no detectable IgE to normal HA. Sera from nonvaccinated individuals, vaccinated individuals who reported no reaction after HDCV booster, and pollen-allergic individuals had no detectable IgE to HDCV, BPL-MRC5, or BPL-HA. Changes in the ratios of pre- to postbooster serum levels of specific IgE to HDCV and BPL-HA were significantly different in a group of 19 individuals who reported reactions to HDCV boosters; these changes in pre- to postbooster IgE levels in nonreactive vaccinees were not significant. Prebooster serum IgE RAST ratios to HDCV or BPL-HA were not predictive of potential reactions to HDCV. A number of experimental BPL-HA reaction mixtures were assayed to examine the effect of variable concentrations of BPL to HA. Increasing relative molar concentrations of BPL to HA resulted in increased electrophoretic mobility, whereas the highest relative specific IgE binding was detected in BPL-HA molar reaction mixtures of approximately 12.5:1.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibody Specificity↗
PubMed1987

Production of an international reference standard alternaria extract. I. Testing of candidate extracts.

As part of a program to establish international standards of selected allergens, 6 coded extracts of Alternaria were assessed in 6 laboratories by immunochemical, biochemical and physicochemical procedures. Direct RAST, RAST inhibition, quantitative skin tests and leukocyte histamine release were used to assign relative orders of potency to the 6 extracts. The composition and major allergen content was tested by thin-layer isoelectric focusing and quantitative immunoelectrophoresis (crossed immunoelectrophoresis and crossed radioimmunoelectrophoresis). Three laboratories determined the quantity of purified allergens in each of the preparations. In addition, source materials were sent to an expert Alternaria taxonomist for independent identification. The results showed considerable variation with respect to total allergenic potency and content of individual allergens. Source materials could not be confirmed as Alternaria in some instances. Based on fulfillment of written specifications and assay results, extract No. 6 was recommended by the Alternaria Working Group as the candidate international standard to the Steering Committee of the Allergen Standardization Subcommittee of the International Union of Immunological Societies.

Allergens↗
PubMed1986

The preparation and testing of the proposed International Reference (IRP) Bermuda grass (Cynodon dactylon)-pollen extract.

A lyophilized candidate extract of Bermuda-grass (Cynodon dactylon) pollen, intended for use as an International Reference Standard, was prepared by pooling four individual candidate extracts. In preliminary investigations, the four candidate extracts encompassed a variety of extraction methods. The collaborative testing program simultaneously analyzed the proposed reference and the individual extracts and included 11 laboratories performing RAST inhibition, histamine release, crossed immunoelectrophoresis, crossed radioimmunoelectrophoresis, isoelectric focusing, sodium dodecyl sulfate gel electrophoresis, and protein determinations with a variety of reagents and methods. The four candidate extracts and the pooled reference were found to be equivalent. The stability of this extract has also been studied. This International Reference Preparation of Bermuda grass-pollen extract should be useful for research and industry.

Allergens↗
PubMed1986

Seasonal variation in antigens of the imported fire ant Solenopsis invicta.

Eight sequentially collected lots of aqueous extracts of imported fire ant (IFA) front end and abdominal end segments were assayed for phospholipase A (PLA), N-acetyl-beta-glucosaminidase (NAG), and hyaluronidase. Relative potency of each extract lot and pooled venom was measured by RAST inhibition against a venom standard. More than a hundredfold difference in PLA activity was observed. Early summer collections had the highest activity. The May to June collection had more than twice the PLA activity of the next most potent lot. Discordancy in enzyme patterns was noted only in AE extract. NAG levels peaked earlier in the spring and summer and fluctuated less widely. Front end extract had lower activity levels for both enzymes, with no seasonal fluctuation in NAG and a single elevation in PLA activity in the April to May collection. RAST inhibition varied directly with PLA activity (p less than .05) but not with NAG nor hyaluronidase activities. Fifty-one percent of systemic allergic reactions to IFA stings occurred in summer, and 19% occurred in spring. A reported demographic survey demonstrated a higher incidence of IFA stings in the spring (39.9%) with a lower attack rate in the summer (31.9%). These findings suggest that the rate of systemic reactions to stings of the IFA may be related to seasonal variations in allergenic potency, as measured by PLA and RAST inhibition, rather than the sting attack rate.

Acetylglucosaminidase↗
PubMed1985

Where does cat allergen 1 come from?

Cat allergen 1, the major allergen from cats, has been demonstrated to be present in surface washing and in saliva. With the use of an immunohistologic technique with monospecific anti-CA 1, we demonstrated two different sources of the protein, mucous salivary glands and hair roots, where it originates from sebaceous glands.

Allergens↗
PubMed1985

A comparative study of the allergens of cat urine, serum, saliva, and pelt.

In direct RAST analyses of sera from 43 individuals with a history of cat allergy, 39.5% were positive to cat pelt, 37.5% to cat saliva, and 12% each to cat urine and serum. The cat pelt and saliva extracts contained allergen 1, but cat serum and cat urine collected by bladder puncture had no detectable levels of this allergen. A crossed immunoelectrophoresis/crossed radioimmunoelectrophoresis analysis failed to reveal any allergen in urine or serum that was not also present in the saliva or pelt preparations, although urine had two allergens not present in serum. When serum from a patient who was direct RAST positive to cat pelt, serum, saliva, and urine was tested by crossed radioimmunoelectrophoresis, it was determined that a total of six allergens were detectable in cat pelt, three in cat urine, and six in cat serum. Since cat serum contains no detectable cat allergen 1, it may be concluded that at least seven allergens derived from the cat are capable of binding to IgE antibody in humans.

Allergens↗
PubMed1984

Production and testing of an international reference standard of short ragweed pollen extract.

A lyophilized candidate International Reference Standard of short ragweed pollen extract was prepared by use of defined source material. In preliminary experiments, this extract was demonstrated by RAST inhibition and crossed radioimmunoelectrophoresis assays to contain several well-characterized ragweed allergens and to contain multiple antigenic bands by crossed immunoelectrophoresis analysis. In a subsequent multinational collaborative study involving 12 laboratories in five countries, the candidate extract was compared with existing national reference or commercial ragweed extracts by a variety of immunochemical, biochemical, and physicochemical procedures. The candidate extract could be used to assign relative orders of potency to the comparison-test extracts. In separate studies, the candidate extract was demonstrated to be stable when it was stored at either -20 degrees C or +5 degrees C for at least 2 yr. The candidate extract has been accepted as an International Reference Standard with an assigned arbitrary potency of 100,000 units per ampule .

Humans↗
PubMed1984

The important sources of German cockroach allergens as determined by RAST analyses.

The important sources of allergens in cockroach were investigated. Aqueous extracts were prepared from American and German cockroach whole body, cast skins, and feces as well as egg shells of German cockroach. Each extract was analyzed for protein content and characterized by electrophoretic analyses. Cockroach specific IgE in the sera of patients and controls was investigated by RAST, by use of paper discs coupled to equal amounts of protein from each extract. The results for German cockroach indicate that whole body and cast skins have equal RAST potencies, egg shells are less potent, and feces are least potent. Reactivity of the same individuals to American cockroach was much lower. RAST-inhibition studies with German cockroach extracts indicate that the same allergens are found in whole body, cast skins, egg shells, and feces. The RAST potencies obtained in the inhibition experiments, in general, agreed with the direct RAST results. The results indicate that cast skins and whole bodies of German cockroaches contain the clinically relevant allergens for this group of cockroach-sensitive patients.

Allergens↗