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A patient with multiple atopic allergies, atopic facial dermatitis, and a generalized atopic skin diathesis developed (i) angioedema of the lips and tongue following ingestion of peanut butter, and (ii) localized urticarial reactions following direct skin contact. Open testing with peanut butter demonstrated probable immunologic contact urticaria. The relationship of contact urticaria to the atopic skin diathesis is discussed.
Acute aflatoxicosis was believed to be the cause of death of 12 to 90 drought-stricken Hereford calves fed peanut hay on the southern Darling Downs in Queensland. Jaundice, photosensitisation, diarrhoea, anorexia and depression were seen before death. Serum levels of enzymes of hepatic origin and bilirubin were elevated. After death haemorrhage, hepatocyte damage, bile ductule proliferation were found. Total aflatoxin levels up to 2230 microgram/kg were detected in the peanut hay with most toxin concentrated in nut-in-shell.
Four soil temperature and moisture treatment regimens were imposed on Florunner peanuts 94 days after planting in experimental plots in 1980. At harvest (145 days after planting), the incidence of the Aspergillus flavus group and the aflatoxin concentration were greatest in damaged kernels. Extensive colonization of sound mature kernels (SMK) by the A. flavus group occurred with the drought stress treatment (56% kernels colonized); colonization was less in the irrigated plot (7%) and the drought stress plot with cooled soil (11%) and was intermediate in the irrigated plot with heated soil (26%). Aflatoxin was virtually absent from SMK with the last three treatments, but it was found at an average concentration of 244 ppb (ng/g) in drought-stressed SMK. Colonization of SMK by the A. flavus group and aflatoxin production were greater with hot dry conditions. Neither elevated temperature alone nor drought stress alone caused aflatoxin contamination in SMK. When the ratio of SMK colonized by A. flavus compared with A. niger was greater than 19:1, there was aflatoxin contamination, but there was none if this ratio was less than 9:1. Irrigation caused a higher incidence of A. niger than drought did. This may have prevented the aflatoxin contamination of undamaged peanuts.
Samples of segregation 3 farmer stock peanuts from the 1980 southeastern United States growing season were analyzed for the presence of cyclopiazonic acid and aflatoxins. Cyclopiazonic acid appeared in 21 of 27 loose-shell kernel fractions at a range of 32 to 6,525 mug/kg and in 4 of 21 sound mature kernel fractions at a range of 32 to 130 mug/kg. Aflatoxins were detected in 26 of 27 loose-shell kernel fractions and in 20 of 21 sound mature kernel fractions. Cyclopiazonic acid used at 105 and 210 mug/kg to spike peanut samples was recovered at an average rate of 93.3%, with ranges of 89 to 119 and 166 to 221 mug/kg, respectively. The minimum detection limit on oxalic acid-impregnated silica gel plates was 26 ng.
A comparison of the invasion of flowers, aerial pegs, and kernels by wild-type and mutant strains of Aspergillus flavus or A. parasiticus along with aflatoxin analyses of kernels from different drought treatments have supported the hypothesis that preharvest contamination with aflatoxin originates mainly from the soil. Evidence in support of soil invasion as opposed to aerial invasion was the following. A greater percentage of invasion of kernels rather than flower or aerial pegs by either wild-type A. flavus or mutants. Significant invasion by an A. parasiticus color mutant occurred only in peanuts from soil supplemented with the mutant, whereas adjacent plants in close proximity but in untreated soil were only invaded by wild-type A. flavus or A. parasiticus. Aflatoxin data from drought-stressed, visibly undamaged peanut kernels showed that samples from soil not supplemented with a mutant strain contained a preponderance of aflatoxin B's (from wild-type A. flavus) whereas adjacent samples from mutant-supplemented soil contained a preponderance of B's plus G's (from wild-type and mutant A. parasiticus). Preliminary data from two air samplings showed an absence of propagules of A. flavus or A. parasiticus in air around the experimental facility.
Three genotypes of peanut (Arachis hypogaea L.), with ICG numbers 221, 1104, and 1326, were grown in three replicate plots and drought stressed during the last 58 days before harvest by withholding irrigation water. Within each plot there were eight levels of stress ranging from 1.1 to 25.9 cm of water. Kernels harvested from the plots were hydrated to 20% moisture and challenged with Aspergillus flavus. Fungal colonization, aflatoxin content, and phytoalexin accumulation were measured. Fungal colonization of non-drought-stressed kernels virtually ceased by 3 days after inoculation, when the phytoalexin concentration exceeded 50 micrograms/g (fresh weight) of kernels, but the aflatoxin concentration continued to rise exponentially for an additional day. When fungal colonization, aflatoxin production, and phytoalexin accumulation were measured 3 days after drought-stressed material was challenged, the following relationships were apparent. Fungal colonization was inversely related to water supply (r varied from -0.848 to -0.904, according to genotype), as was aflatoxin production (r varied from -0.876 to -0.912, according to genotype); the phytoalexin concentration was correlated with water supply when this exceeded 11 cm (r varied from 0.696 to 0.917, according to genotype). The results are discussed in terms of the critical role played by drought stress in predisposing peanuts to infection by A. flavus and the role of the impaired phytoalexin response in mediating this increased susceptibility.
Peanut kernels (Tainan 9, a Spanish cultivar) inoculated with Aspergillus parasiticus, A. flavus, A. niger, or A. ochraceus as well as noninoculated kernels were incubated in a humidified environment (relative humidity, 100%) at 25(deg)C for 7 weeks. Internal fungal populations and changes in moisture and sucrose content and free amino acid composition of the kernels were determined periodically. Fungal populations determined by using A. flavus and A. parasiticus agar and rose bengal chlortetracycline agar as enumerating media were closely correlated. Moisture content in the kernels increased from 5.8 to 20.4% (dry basis), and changes in individual free amino acid contents varied, depending upon the incubation time and type of fungus used as an inoculum. In the early infection period (up to 5 weeks), sucrose contents and logarithms of threonine and tyrosine contents increased while logarithms of free glutamic acid content decreased linearly with incubation time. A negative linear relationship was further obtained between logarithms of fungal populations and the logarithm of free glutamic acid content (R(sup2) > 0.80) of the infected peanut kernels.
Symbiotic gene diversity and other measures of genetic diversity were examined in Bradyrhizobium isolates that form an effective symbiosis with peanut (Arachis hypogaea). Initially, restriction fragment length polymorphism (RFLP) analysis using a nitrogenase (nif) gene probe was performed on 33 isolates along with one Bradyrhizobium elkanii and two Bradyrhizobium japonicum strains. Considerable diversity was observed among the RFLP patterns of many of the isolates, especially those from South America. Some isolates, however, were found to have similar nif and subsequent nod (nodulation) gene RFLP patterns, indicating symbiotic gene relatedness. With some noted exceptions, symbiotic gene relatedness correlated with relatedness based on total DNA homology and ribotyping analyses. Symbiotic gene relatedness also correlated with symbiotic effectiveness. The RFLP and DNA homology analyses indicate that bradyrhizobia effective with peanut are genetically diverse and consist of at least three different species. This diversity, however, was not particularly evident with partial 16S rRNA gene sequencing. Sequences obtained from the isolates were very similar to each other as well as to sequences previously reported for other Bradyrhizobium strains.
Two forms of cationic peroxidase from peanut cells were differentiated by concanavalin A affinity chromatography. They differed in molecular mass as well as concanavalin A binding, leading to the initial suggestion that they represented two isozymes of peroxidase. However, similar values for the specific activity, Soret absorption, calcium content, and peptide molecular mass were observed for each of the forms. Therefore, the binding and nonbinding fractions most likely represent two molecular forms of cationic peanut peroxidase, rather than two distinct cationic isozymes. The difference between these two forms is discussed in terms of glycosylation. Through the amino acid sequence analysis of the formic acid treated peptide, the cationic isozyme has been shown to be identical in amino acid sequence to the cDNA clone PNC1.
As part of a project to characterize molecules involved in the crack-entry infection process leading to nodule development, a microscopic assay was used to visualize the attachment of cells of Bradyrhizobium sp. strains SEMIA 6144 and TAL 1000 (labelled by introducing a plasmid expressing constitutively the green fluorescent protein GFP-S65T) to Arachis hypogaea L. (peanut). Qualitative and quantitative results revealed that attachment was strongly dependent on the growth phase of the bacteria. Optimal attachment occurred when bacteria were at the late log or early stationary phase. Cell surface proteins from the Bradyrhizobium sp. strains inhibited the attachment when supplied prior to the attachment assay. Root incubation with a 14-kDa protein (eluted from sodium dodecyl sulphate - gel electrophoresis of the cell surface fraction) prior to the attachment assay resulted in a strong decrease of attachment. The adhesin appeared to be a calcium-binding protein, since cells treated with EDTA were found to be able to bind to adhesin-treated peanut roots. Since this protein has properties identical to those reported for rhicadhesin, we propose that this adhesin is also involved in the attachment process of rhizobia to root legumes that are infected by the crack-entry process.
Food allergies, particularly to peanuts, are a common cause of anaphylaxis. Approximately 125 people die each year in the USA secondary to food-induced anaphylaxis. Clinical anaphylaxis is a syndrome of diverse etiology and dramatic presentation of symptoms associated with the classic features of type I, IgE-mediated hypersensitivity [1]. Typically the term anaphylaxis connotes an immunologically-mediated event that occurs after exposure to certain foreign substances. This reaction results from the generation and release of a variety of potent biologically active mediators and their concerted effects on various target organs. Anaphylaxis is recognized by cutaneous, respiratory, cardiovascular, and gastrointestinal signs and symptoms occurring singly or in combination. This article focuses on allergic reactions to peanuts that manifest as signs and symptoms involving multiple target organs or the cardiovascular system alone.
BACKGROUND: The identification of IgE epitopes for proteins is the first step in understanding the interaction of allergens with the immune system. Proteins from the legume family have shown in vitro cross-reactivity in IgE-binding assays, but this cross-reactivity is rarely clinically significant. Resolution of this discrepancy requires IgE epitope mapping of legume family protein allergens. METHODS: We constructed six fusion proteins representing overlapping regions of soybean glycinin G1 acidic chain. These fusion proteins were used in immunoblotting and a novel sandwich ELISA with pooled sera from soy-allergic individuals to reveal a common IgE-binding region. This region was the focus for IgE epitope mapping using overlapping synthetic peptides. RESULTS: Data from the fusion protein experiments revealed an IgE-binding region consisting of residues F192-I265. Analysis of the overlapping synthetic peptides to this region indicated that IgE epitopes to glycinin G1 acidic chain consist of residues G217-V235 and G253-I265. The epitopes identified for glycinin G1 acidic chain are homologous to IgE epitopes previously identified for the peanut allergen Ara h 3 [1]. However, residues identified by alanine scanning in the peanut epitopes as being important for IgE binding are different in the natural soybean epitopes. CONCLUSIONS: The IgE epitopes identified for glycinin G1 acidic chain apparently represent an allergenic region of several legume family seed storage proteins. Our findings indicate that the identification of IgE epitopes and structural analysis of legume family proteins will provide valuable information to the study of food allergies.
Arachis hypogea (peanut, groundnut), an annual oil seed belonging to the Leguminosae family and the Papillionacea subfamily, is a legume native to South America but now grown in diverse environments in six continents between latitudes 40 degrees N and 40 degrees S. Arachis hypogea can grow in a wide range of climatic conditions. The low yields of this crop are mainly attributed to unreliable rainfall patterns with frequent droughts, lack of high-yielding adapted cultivars, damage by diseases and pests, poor agronomic practices, and limited use of inputs. Genetic engineering approaches have been shown to be comparatively fast, leading to better isolation and cloning of desired traits for combating the various biotic and abiotic stresses. This chapter describes an Agrobacterium-mediated transformation protocol in peanut using the cotyledon system. The system described here is potentially applicable to a vast range of genotypes with a high transformation frequency of >70% based on the preliminary molecular data, indicating the production of a large number of independently transformed transgenic plants. The method reported here provides opportunities for crop improvement of this important legume crop via genetic transformation.
BACKGROUND: Peanut (PN) and tree nut (TN) allergies are potentially life-threatening, rarely outgrown, and appear to be increasing in prevalence. However, there is relatively little reported about the clinical features of acute reactions to these foods and their potential association. OBJECTIVE: To describe the clinical features of acute reactions during initial and subsequent accidental ingestions of PN and TN among children with a history of at least one acute allergic reaction to these foods. DESIGN: Questionnaire survey, examination, and serologic testing for specific IgE antibody of patients with convincing histories of acute reactions (at least one organ system involved within 60 minutes of ingestion) to PN or TN. RESULTS: A total of 122 patients (63% males; median age, 8 years at time of study) had acute reactions; 68 had reactions only to PN, 20 only to TN, and 34 to both PN and TN. Of those reacting to TN, 34 had reactions to one, 12 to two, and 8 to three or more different TN, the most common being walnut, almond, and pecan. Initial reactions usually occurred at home (median age, 24 months for PN and 62 months for TN) and were considered to result from a first exposure in 72% of cases. Eighty-nine percent of the reactions involved the skin (urticaria, angioedema), 52% the respiratory tract (wheezing, throat tightness, repetitive coughing, dyspnea), and 32% the gastrointestinal tract (vomiting, diarrhea). Two organ systems were affected in 31% of initial reactions, and all three in 21% of reactions. Thirty-eight of 190 first reactions to PN or TN were treated with epinephrine. Accidental ingestions occurred in 55% of PN-allergic children (average of two accidents per patient with an accidental ingestion) and in 30% of TN-allergic children over a median period of 5.5 years. On average, symptoms after accidental exposure were generally similar to those at initial exposure. Accidents occurred commonly in school but also at home and in restaurants. Modes of accidental ingestion included sharing food, hidden ingredients, cross-contamination, and school craft projects using peanut butter. Eighty-three percent of the children were breastfed, with >90% of the mothers ingesting PN and at least one TN during lactation. Among patients reporting no history of exposure (>60% of patients for each TN), IgE antibodies were found to a particular TN in 50% to 82% of patients and to PN in 100% of patients. CONCLUSIONS: Acute allergic reactions to PN occur early in life. PN and TN allergic reactions coexist in one third of PN-allergic patients, frequently occur on first known exposure, and may be life-threatening, requiring emergency treatment. Accidental ingestions are common, occur frequently outside of the home, and often require emergency treatment. Consequently, early diagnosis followed by education on avoidance and treatment measures (including self-administered epinephrine) is imperative.
The concept of a linear increase in harvest index, dHI/dt, has proven very useful for crop simulation modeling. The effect of high temperature on the response of dHI/dt of pods and seeds of peanut (Arachis hypogaea L.) has not been described. The objectives of this work were to determine (i) whether dHI/dt was linear at high temperature, (ii) whether high temperature affected dHI/dt and/or the timing of the linear phase of increase in HI, and (iii) whether there was genotypic variation in the response of dHI/dt to high temperature. Four peanut genotypes varying in heat tolerance were grown in pots at either 28/22 or 38/22 degrees C from 21 to 90 d after planting (DAP). Plants were harvested on 10 occasions starting 27 DAP and total dry matter accumulation and partitioning measured. High temperature reduced total dry weight by 20 to 35%, seed HI by 0 to 65%, and seed dry weight by 23 to 78%. At 28/22 degrees C, dHI/dt for pods and seeds was linear and varied from 0.0058 to 0.0109 d(-1). At 38/22 degrees C, dHI/dt of pods and seeds was also linear and varied from 0.0028 to 0.0089 d(-1). There were genotypic differences in response to temperature. High temperature had no effect on dHI/dt in moderately tolerant genotypes 796 and 47-16. In susceptible genotypes ICGV 86016 and ICGV 87282, however, the start of pod and seed filling was delayed by 5 to 9 d and dHI/dt reduced by 20 to 65% at 38/22 degrees C. Reductions in pod and seed dry weight at 38/22 degrees C were therefore due to reductions in total dry matter and dHI/dt, depending on the heat tolerance of the genotype. Crop models need to account for genotypic differences in the response of timing and rate of dHI/dt to high temperature to successfully simulate yields in warmer environments.
Steers (n = 156) finished on rhizoma peanut (Arachis glabrata Benth.)-tropical grass pasture in Florida and slaughtered at Central Packing, Center Hill were compared with steers (n = 152) finished on a concentrate diet in Texas and slaughtered at Excel, Plainview. Average daily gain during the growing and finishing periods was lower (P < .001) for forage-finished steers (.49 and .94 kg/d, respectively) than for concentrate-finished steers (.78 and 1.33 kg/d, respectively). Forage-finished steers had less fat over the ribeye (8.3 vs 11.4 mm; P < .01), lighter hot carcass weight (280 vs 346 kg; P < .001), and smaller longissimus muscle area (70.8 vs 86.6 cm2; P < .001) than concentrate-finished steers. Yield grade was not different (2.7 vs 2.6; P > .10), but quality grade was slightly better (low Select vs mid Select; P < .01) for concentrate-finished steers. Lean color of forage-finished steers was darker (P < .001) and fat of forage-finished steers had a creamier color (P < .001), but carcasses were not discounted due to yellow fat color. Shear force values were higher (6.8 vs 4.0 kg; P < .001) for forage-finished than for concentrate-finished steers. Off-flavors were detected by trained sensory panelists in 36% of forage-finished and 14% of concentrate-finished carcasses, but all at barely detectable levels. This research indicates that steers can be finished on rhizoma peanut-tropical grass pastures, but with some reduction in quality grade relative to concentrate-finished steers.(ABSTRACT TRUNCATED AT 250 WORDS)
Metabolism and feedlot trials were conducted to evaluate increased dietary urea as a method of reducing detrimental effects of peanut skin (PS) tannins on nutrient digestibility and finishing steer performance. The PS fed in the trials contained 17.8% crude protein and 20.1% tannin. Urea (.7%) was included in a control (C) diet without PS, and with 15% PS in low-urea (.3%; LUPS), moderate-urea (.7%; MUPS) and high-urea (1.1%; HUPS) diets that contained ground corn and 15% peanut hulls. Apparent digestibility coefficients for dry matter, organic matter and crude protein were higher (P less than .05) for the C diet than for PS diets. Fecal N (g/d) was consistently higher (P less than .05) for PS diets than for the C diet. Retained N (g/d) was similar for steers fed C and HUPS diets, but lower (P less than .05) than C for LUPS and MUPS diets. Average daily gain at 91 d was highest (P less than .05) for C steers in the feedlot, intermediate (P less than .05) for MUPS and HUPS steers and lowest (P less than .05) for LUPS steers. Feed:gain ratio was 97% higher (P less than .05) for LUPS steers compared with C steers, but average daily feed intake was similar for all treatments. Rumen fluid propionic acid was lower (P less than .05) on all PS diets compared with the C diet on d 90. Plasma urea nitrogen (d 90) was reduced (P less than .05) by 48.5, 55.5 and 57.6%, respectively, on LUPS, MUPS and HUPS diets compared with the C diet.(ABSTRACT TRUNCATED AT 250 WORDS)
Peanut stover (PS) is similar to full-bloom alfalfa hay in chemical composition. The objective of this study was to assess the effect of adding raw or heated corn meal to PS at ensiling on silage N components, fermentation acids, and digestion by ruminal microorganisms. The PS was collected after harvesting of peanuts and ensiled immediately without and with addition of raw or heated corn meal (100 g/kg of fresh weight). Corn was added to PS so that the initial mixture would contain adequate dry matter (DM) (approximately 30%) and additional nonfiber carbohydrate to enhance silage fermentation. After 8 wk of silo fermentation, corn-treated silages contained less structural carbohydrates but more non-fiber carbohydrates compared with the untreated control. A shift from hemicellulose to nonfiber carbohydrate use during silage fermentation was evident by corn treatment. Additional corn at ensiling resulted in silage N with less water-soluble N, protein N, nonprotein N, nonprotein nonammonia N (peptides plus amino acids), and ammonia N. Based on changes in soluble nonprotein N before and after ensiling, the amount of proteolysis was approximately 66% for control silage and was nearly 40% lower in response to corn treatment. Adding corn increased silage lactic acid, but both acetic and propionic acids decreased. These changes were reflected in the lower pH and higher fermentation efficiency with corn-treated silages. More DM was digested and greater amounts of volatile fatty acids, except for branched-chain acids, were produced in vitro by ruminal microorganisms with corn-treated silages. In addition, incubations with silage treated with heated corn contained higher concentrations of acetic and propionic acids compared with raw corn. In vitro ammonia accumulation per unit of DM digested was lower for corn treatments than the control, and for heated corn vs. raw corn-treated silage. These results indicate that supplementation of either raw or heated corn on PS at ensiling could minimize proteolysis and improve fermentation efficiency. Advantages from using heated vs. raw corn could extend beyond silage fermentation and include rumen microbial fermentation.