Demonstration of auto-anti-idiotypic antibody cross-reacting with public idiotypic determinants in the serum of rye-sensitive allergic patients

The present study documents the presence, in the serum of one allergic individual, of auto-anti-idiotypic antibodies cross-reacting with public idiotypic determinants expressed on human IgE and IgG anti-Rye I antibodies. Sera from rye-sensitive patients were tested for specific IgG and IgE antibodies to Rye I by double antibody. The IgG fraction, isolated from the serum of a patient with a history of previous hyposensitization therapy, was repeatedly absorbed on Rye-I-Sepharose as well as on IgM- and IgG-Sepharose to remove anti-Rye I antibodies as well as any possible anti-heavy or light chain activity. This IgG fraction, named anti-idiotypic fraction (a-IdF), blocked in a dose-dependent fashion the reaction of IgG and IgE anti-Rye I antibodies with Rye I antigen. The a-IdF also blocked the binding of anti-rye antibodies to Rye I antigen in the serum of 20 unrelated allergic patients, indicating that these anti-Rye I antibodies bore public idiotypic determinants.     

Effect of selenium and vitamin E dietary deficiencies on chick lymphoid organ development

Diets specifically deficient in selenium (Se) and/or vitamin E or adequate in both nutrients were fed to chicks from the time of hatching. Lymphoid organs (bursa, thymus, and in some instances, spleen) were collected from chicks 7-35 days of age. Growth of the chicks fed these diets was monitored over the experimental period as was lymphoid organ growth. The development of the primary lymphoid organs was further assessed by histological techniques and the organ contents of vitamin E (alpha-tocopherol) and Se were determined. Specific deficiencies of either Se or vitamin E were found to significantly impair bursal growth as did a combined deficiency. Thymic growth was impaired only by the combined deficiency diet. Severe histopathological changes in the bursa resulted from the combined deficiency and these were detectable by 10-14 days after hatching. These changes were characterized by a gradual degeneration of the epithelium and an accompanying depletion of lymphocytes. Similar changes, although slower to develop and less severe, were observed in the thymus as a result of the combined deficiency. When both serum and tissue levels of vitamin E and Se were monitored, it was observed that these were rapidly and independently depleted by the specific deficiency diets. These data suggest that the primary lymphoid organs are major targets of Se and vitamin E dietary deficiencies and provide a possible mechanism by which immune function may be impaired.     

Early growth of wheat embryonic axes and the synthesis of RNA and DNA

The requirement for the synthesis of RNA and DNA in early germination of wheat (Triticum aestivum var Newana) embryonic axes has been studied by incubating embryos in the presence of appropriate inhibitors and monitoring both embryo growth and the rates of specific metabolic processes. Experiments with 5-fluorouridine showed that both rRNA and DNA synthesis could be curtailed by 60 to 70% without affecting embryo growth to 24 hours. Similarly, the presence of mitomycin C and methotrexate inhibited DNA synthesis 70%, with only a small effect on growth. Experiments with a range of concentrations of cordycepin and α-amanitin indicated that mRNA synthesis could be curtailed by 30 to 40% within the first 8 hours of germination with only a small effect on embryo growth. Thus, at least the initial phases of seed embryo germination are not closely linked to the synthesis of mRNA, rRNA, or DNA. Maximal sensitivity of embryo growth was obtained with cycloheximide and 2-(4-methyl-2,6-dinitroanilino)-N-methyl propionamide, supporting the idea that protein synthesis is the macromolecular process most closely linked to early germination.     

Antigens of Ambrosia elatior (short ragweed) pollen. III. Crossed radioimmunoelectrophoresis of ragweed-allergic patients' sera with special attention to quantification of IgE responses

Short ragweed allergenic extract has been studied by means of crossed radioimmunoelectrophoresis (CRIE) with the use of sera from 37 allergic patients and the relevant control sera. In this study 22 of 52 antigens, detectable in crossed immunoelectrophoresis (CIE) against polyspecific rabbit anti-ragweed IgG, were able to bind specific human IgE to their corresponding immunoprecipitates. This binding was semiquantified by comparison with the binding of a standard serum pool. Nine antigens were identified as important allergens, including the previously isolated components, AgE, AgK, and Ra6. Certain allergens (e.g., AgE, AgK, and Ag 31) bound IgE in almost all patients' sera, whereas others showed a bimodal distribution for sera of responder and nonresponder patients. The total CRIE score was found to correlate significantly both with ragweed-specific serum IgE antibody determined by RAST (rs = 0.88; p less than 0.001) and with total IgE level (rs = 0.55; p less than 0.01). Patient's CRIE scores to AgE also correlated significantly with their specific IgE antibody to AgE measured by RIA (r = 0.47; p less than 0.01) and with skin-test sensitivity to AgE (r = 0.44; p less than 0.05). It was concluded that CRIE is well suited for identification of important ragweed allergens without the previous need for laborious isolation procedures.     

A spin probe study of the influence of cholesterol on motion and orientation of phospholipids in oriented multibilayers and vesicles

Spin probes have been used to study at the molecular level the influence of cholesterol on bilayers of egg lecithin and dipalmitoyl lecithin. Distinct differences between the two lecithin systems were revealed. Increasing amounts of cholesterol result in extension of the fatty acid chains and decreased amplitude of motion of the long axes of the fatty acids in egg lecithin. In dipalmitoyl lecithin cholesterol causes an increase in the mobility and amplitude of motion of the fatty acid side chains, presumably due to alteration of the molecular interactions between phospholipids by relaxing the close packing of these molecules. These data provide an explanation for the condensing and fluidizing effects of cholesterol in water-containing phases and monolayers of egg lecithin and dipalmitoyl lecithin, respectively, and for the permeability behavior of egg lecithin and dipalmitoyl lecithin liposomes in the presence and absence of cholesterol. Differences are revealed between the spin bilayer environments in hydrated phospholipid films and vesicles.     

The stereochemistry of the hydrogen elimination in the biological conversion of cholest-7-en-3β-ol into cholesterol

1. The syntheses of Δ⁷-[4-¹⁴C]cholestenol (XVI, Scheme 3) and Δ⁷-[6α-³H]-cholestenol (XII, Scheme 2) are described. 2. The metabolism of doubly labelled Δ⁷-cholestenol (II, Scheme 1) by rat-liver homogenates was studied. 3. During the enzymic conversion of Δ⁷-cholestenol into cholesterol (IV, Scheme 1) the 6α-hydrogen atom of the former is lost and the overall reaction corresponds to a cis-elimination. 4. In the light of these results various mechanisms for the conversion of Δ⁷-cholestenol into cholesterol are discussed.     

Audit of 26 years of obstetrics in general practice.

To assess the feasibility and quality of general practitioner obstetrics an audit of 1223 consecutive obstetric deliveries over 26 years was carried out with standard clinical records. The perinatal mortality of 9.0 per 1000 births was significantly better than the national average of about 19.0 per 1000 for the overall period. During the audit home deliveries virtually stopped. The proportion of consultant bookings and deliveries more than doubled because of more stringent booking arrangements despite relocation of the previously isolated general practitioner unit to beneath the consultant unit. Abnormal deliveries also rose significantly. A "steady state" was achieved during the final 11 years in which 73% of women booked to be delivered by their general practitioner, 64% were admitted to the general practitioner unit, and 54% were delivered by their general practitioner. Though this is enough to sustain obstetric experience, the proportion might safely be increased.     

Formation of mutagens during the frying of Hawaiian fish: correlation with creatine and creatinine content

Compounds mutagenic toward Salmonella typhimurium strain TA98 in the presence of rat-liver homogenates (S9) were formed when fish flesh was fried at 199 degrees C. Three species of Hawaiian fish commonly consumed in Hawaii (skipjack tuna, Katsuwonus pelamis; yellowfin tuna, Neothunnus macropterus; and milkfish, Chanos chanos) were cooked in an electric skillet, along with samples of sole (Microstomus pacificus). Organic extracts of the fish were tested in the Ames Salmonella mutagenic assay using tester strain TA98 and S9. Basic organic extracts of fried, but not raw, samples exhibited significant mutagenicity. The levels of mutagenicity were also higher among the red flesh Hawaiian fish ('ahi, aku and awa) than with the white flesh sole. Creatine and creatinine contents were highest in the Hawaiian fish and lower in the sole. Creatine levels in the fish were 50-100 times greater than the creatinine content and varied from a high of 645 mg/100 g wet weight of fish for yellowfin tuna to a low value of 251 mg/100 g for sole. Mutagen levels are only approximately related to creatine/creatinine levels suggesting that other components contained in these fish may be as important as the guanidines in determining the levels of mutagen in the cooked fish.     

The application of pH-sensitive spin labels to studies of surface potential and polarity of phospholipid membranes and proteins.

The effects of pH titration on the EPR spectra of imidazolidine nitroxides located at the surface of mixed bilayers composed of dimyristoylphosphatidylglycerol (DMPG) and dimyristoylphosphatidylcholine (DMPC), and at the surface of the protein, human serum albumin (HSA), have been investigated. It is found that the shift in pKa of the amino group of the imidazolidine radical from its value of 4.6 in water depends both on the interfacial polarity (delta pKapol) and on the electrostatic surface potential (delta pKael) when it is positioned at the bilayer/water interface by an anchoring hydrocarbon tail. The polarity shift is determined to be: delta pKapol = -1.3 units at the surface of DMPC bilayers at 17 degrees C, corresponding to an effective interfacial dielectric constant of epsilon approximately 37, and depends on the temperature with a coefficient of d delta pKapol/dT approximately -0.01 per degree. The electrostatic shift at the surface of DMPG bilayers is delta pKael = +1.6 units in 0.1 M KCl, which corresponds to an electrostatic surface potential of -95 mV. This electrostatic shift depends strongly both on ionic strength and on the fraction of charged lipid in the DMPC/DMPG mixtures, in a manner that agrees with the predictions of electrostatic double-layer theory. It is found that the shift in pKa of an imidazolidine radical covalently bound at the surface of HSA is determined mainly by the surface electrostatics (delta pKapol approximately 0) and corresponds to an electrostatic potential of +33 mV in 0.01 M KCl at a pH below the isoelectric point of the protein.