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Effect of peanut oil and randomized peanut oil on cholesterol and oleic acid absorption, transport, and distribution in the lymph of the rat.

Peanut oil was shown to be atherogenic in cholesterol-fed rats, rabbits, and monkeys. However, after randomization, a process in which the fatty acids in peanut oil are randomly rearranged, its atherogenicity was significantly reduced in cholesterol-fed rabbits and monkeys. The mechanism for this effect remains unknown. This study was designed to investigate whether the absorption, transport and distribution of dietary cholesterol and oleic acid in the lymph were altered in the presence of peanut oil or randomized peanut oil. Previous investigators collected lymph through the mesenteric duct for 6 h and analyzed lymph for cholesterol. In the present study, lymph fluids were collected at timed intervals for up to 8 h and then at 24 h via the thoracic duct. Cholesterol and oleic acid (fatty acid) were estimated not only in the whole lymph but also in lymph lipoprotein fractions and in major lipid fractions. A 24-h lymph collection will enhance accuracy as short-term fluctuations in lipid absorption will not affect the results. Thoracic duct lymph collection is quantitative compared to mesenteric duct lymph collection, which provides only a fraction of the total lymph. Rats were given a lipid emulsion containing either peanut oil or randomized peanut oil. The emulsion also contained cholesterol, oleic acid, and sodium taurocholate in saline and was given through a duodenal catheter. Results show that absorption, transport, and distribution of cholesterol and oleic acid in the lymph fluids were similar in both dietary groups. These results suggest that the atherogenicity of peanut oil may be due to other events taking place subsequent to the release of cholesterol-containing chylomicrons and very low density lipoprotein by the small intestinal epithelial cells into the blood or may be due to the triglyceride structure itself.

Animals↗

The 18 kDa peanut oleosin is a candidate allergen for IgE-mediated reactions to peanuts.

BACKGROUND: Peanut allergy is one of the five most frequent food allergies in children and in adults. Recently, we purified and evaluated the allergenicity of peanut oleosins, a family of small-sized proteins involved in the formation of peanut oil bodies. METHODS: Allergenicity of the purified native protein and of the recombinant protein was tested by Western blot and by IgE-RIA. RESULTS: We found IgE-binding with oleosin in 3 of 14 sera of patients who had suffered an allergic reaction to peanuts. Two sera reacted weakly against 16-18 kDa proteins corresponding to oleosin monomers, in Western blot. The main reacting bands had a molecular size estimated at approximately 34 kDa, approximately 50 kDa and approximately 68 kDa and could therefore correspond to oleosin oligomers. IgE reactivity was higher in extracts from roasted peanuts. The same phenomenon occurred with crude soybean oil fraction, with two bands of 16.5 and 24 kDa corresponding to monomers, and two bands of 50 kDa and 76 kDa corresponding to dimers and trimers, respectively. The 18 kDa band was observed in the 3 Western blots of a membrane-enriched fraction of recombinant oleosin produced in the Sf9-baculovirus expression system (performed with the 3 patient sera). CONCLUSIONS: We have characterized a new peanut allergen which belongs to the oleosins, a family of proteins involved in the formation of oil bodies. The protein may be involved in some of the allergic cross-reactions to peanuts and soybeans.

Allergens↗

Risks of milk formulas containing peanut oil contaminated with peanut allergens in infants with atopic dermatitis.

Four cases of infants with atopic dermatitis are reported. In all cases, a sensitization to peanut is demonstrated. Any ingestion of peanuts can be excluded, with the exception of a daily consumption of peanut oil, contained in milk formulas. Oral challenges with peanut oil induce a rash, and elimination of these brands is followed by the disappearance of eczematous lesions. The presence of residual allergenic proteins in peanut oil is thus suspected. Owing to the growing incidence of peanut hypersensitivity, the elimination of peanut oil from all milk formulas, food for babies, and ointments, seems to be highly advisable.

Allergens↗

Glucocorticoid receptors and in vitro corticosensitivity of peanut-positive and peanut-negative human thymocyte subpopulations.

In 6 human thymus glands, the immature subset of thymocytes was separated from the more mature one, by differential peanut lectin agglutination. These 2 cell subpopulations were analyzed for glucocorticoid receptor content by using a whole cell assay, with (3H)-triamcinolone acetonide as tracer. The unagglutinated thymocytes (peanut negative) contained about 2 times more receptor sites per cell than agglutinated (peanut positive) ones (7650 +/- 1550 S.D. verus 3195 +/- 896 S.D.). The affinity for steroid was similar in both cell subsets, as was the stereospecificity for glucocorticoids, the time-course of steroid-receptor association, and cytoplasmic to nuclear translocation. Despite the greater number of glucocorticoid receptor sites, the peanut-negative thymocyte subpopulation did not differ from the peanut-positive one in its sensitivity to the inhibitory effects of triamcinolone acetonide, as determined by measurements of the incorporation of radiolabeled precursors of protein and DNA. Moreover, the peanut-negative subset appeared more resistant in vitro to the steroid-induced cell lysis as compared to the peanut-positive one. Thus, our data suggest that glucocorticoid receptor density and corticosensitivity are not directly correlated and that the number of glucocorticoid receptor sites may be dependent on the degree of immunologic maturation.

Binding Sites↗

Relationships of sweet, bitter, and roasted peanut sensory attributes with carbohydrate components in peanuts.

Certain roasted peanut quality sensory attributes have been shown to be heritable. Currently the only means of measuring these traits is the use of a trained sensory panel. This is a costly and time-consuming process. It is desirable, from a cost, time, and sample size perspective, to find other methodologies for estimating these traits. Because sweetness is the most heritable trait and it has a significant positive relationship to the roasted peanut trait, the possible relationships between heritable sensory traits and 18 carbohydrate components (inositol, glucose, fructose, sucrose, raffinose, stachyose, and 12 unknown peaks) in raw peanuts from 52 genotypes have been investigated. Previously reported correlations among sweet, bitter, and roasted peanut attributes were evident in this study as well. Where there was positive correlation of total sugars with sweetness, there also was positive correlation of total sugars with roasted peanut attribute and negative correlation of total sugars with bitterness and astringency. The expected generalized relationship of total sugars or sucrose to sweetness could not be established because the relationship was not the same across all market-types. Further work is needed to determine the nature of the chemical components related to the bitter principle, which appear to modify the sweet response and interfere with the sensory perception of sweetness, particularly in the Virginia market-type. Also, certain carbohydrate components showed significant relationships with sensory attributes in one market-type and not another. These differential associations demonstrate the complexity of the interrelationships among sweet, bitter, and roasted peanut sensory attributes. Within two market-types it is possible to improve the efficiency of selection for sweetness and roasted peanut quality by assaying for total carbohydrates. On the basis of the regression values the greatest efficiency would occur in the fastigiate market-type and then the runner.

Arachis↗

Peanut milk and peanut milk based products production: a review.

Since the early 1950s, numerous reports have been published suggesting that peanut milk and peanut milk based products can be prepared in a wide variety of ways. Emphasis has shifted from preparing inexpensive milk like beverages, very nutritious but somewhat lacking consumers appeal, to using the peanut milk or peanut protein isolates as an animal milk extender without changing flavor, to develop more attractive fermented products, and to precipitate proteins from the milk in order to get a curd called "tofu," and to produce cheese analogs. Great attention has been paid to the improvement of the stability, sensory properties, and shelf-life of the milk, using physical and chemical treatments. Many efforts have been deployed for supplementing the products. Thanks to recent advances, the removal of aflatoxin from peanut milk can be achieved using Flavobacterium aurantiacum as a biodegradater. It has also found application as liquid coffee whitener. However, despite all these developments and publications, there is still a need for much more diversified studies in order to definitely overcome the stability, the nutty flavor, and sensory problems always encountered when producing peanut milk and some peanut milk based products.

Arachis↗

Food allergen (peanut)-specific TH2 clones generated from the peripheral blood of a patient with peanut allergy.

BACKGROUND: Increasing evidence indicates a prominent role of allergen-specific TH2 cells, with high IL-4 and IL-5 production and low interferon-gamma production, in the regulation of IgE and eosinophil production in allergic disorders. However, most studies have concentrated on T cells reactive with inhalation allergens, whereas little is known about the properties of food allergen-reactive T cells. OBJECTIVES: In this study we therefore characterized peanut-specific T cells, cloned from a patient with severe peanut allergy. METHODS: Peripheral blood mononuclear cells from patients with peanut allergy and nonallergic individuals were stimulated with crude peanut extract (CPE) to compare the proliferative responses and to select a suitable patient for the cloning of CPE-specific T cells. The resultant panel of CPE-reactive T-lymphocyte clones was serologically phenotyped by flow cytometry and analyzed for cytokine secretion by ELISA. RESULTS: The patients' peripheral blood mononuclear cells showed a dose-dependent proliferation response to CPE, which was significantly higher (p < 0.05) than in peripheral blood mononuclear cells of nonallergic donors. The CPE-specific T-lymphocyte clones generated from the selected patient were all CD4+/CD8- T helper cells with a TH2 cytokine profile, secreting high amounts of IL-4 and IL-5, but little or no interferon-gamma. CONCLUSIONS: This study demonstrates that peanut-specific T cells do occur in the peripheral blood of patients with peanut allergy and suggests an increased frequency of these T cells in patients compared with nonallergic control subjects. The CD4+ phenotype and the TH2 cytokine profile of the CPE-specific T-lymphocyte clones suggest a functional role of allergen-specific TH2 cells in the pathophysiology of food allergy, similar to the function of inhalation allergen-specific TH2 cells.

Adult↗

Perceived prevalence of peanut allergy in Great Britain and its association with other atopic conditions and with peanut allergy in other household members.

BACKGROUND: Despite increasing awareness of peanut allergy, little is known of its prevalence. We report on a two-stage interview survey conducted in Great Britain. METHODS: A total of 16434 adults (aged 15+ years) reported their own allergies and atopies and named cohabitants with peanut allergy (stage 1). Follow-up interviews were conducted with identified sufferers from peanut allergy (stage 2). RESULTS: At stage 1, peanut allergy was reported in 58 respondents and 205 other household members. When we accounted for cases where peanut allergy was unconfirmed or newly reported at stage 2, the prevalence, based on 124 confirmed sufferers, was estimated as 0.48% (95% confidence interval 0.40%-0.55%). The prevalence in children (0.61%, 0.41%-0.82%) was slightly higher than in adults; age-of-onset was strikingly earlier. Prevalence was strongly associated with other atopies, particularly tree-nut allergy. Cases tended significantly to cluster in households. Half of cases had never consulted a doctor. Exactly 7.4% reported being hospitalized after a reaction. CONCLUSIONS: Peanut allergy is reported by 1 in 200 of the population and is commoner in those reporting other atopies. The fact of similar rates in children and adults argues against a recent marked rise in prevalence. The frequency and potential lethality of this disorder emphasize the need for sufferers to demographic factors, other food allergies, atopic conditions, and allergy in family/household members. Our study comprised a screening survey and detailed interviews with sufferers identified. The frequency and potential lethality of this disorder emphasize the need for sufferers to receive correct medical advice on management [corrected].

Adolescent↗

Peanut allergen Ara h 3: isolation from peanuts and biochemical characterization.

BACKGROUND: Peanut allergen Ara h 3 has been the subject of investigation for the last few years. The reported data strongly depend on recombinant Ara h 3, since a purification protocol for Ara h 3 from peanuts was not available. METHODS: Peanut allergen Ara h 3 (glycinin), was purified and its posttranslational processing was investigated. Its allergenic properties were determined by studying IgE binding characteristics of the purified protein. RESULTS: Ara h 3 consists of a series of polypeptides ranging from approximately 14 to 45 kDa that can be classified as acidic and basic subunits, similar to the subunit organization of soy glycinin. N-terminal sequences of the individual polypeptides were determined, and using the cDNA deduced amino-acid sequence, the organization into subunits was explained by revealing posttranslational processing of the different polypeptides. IgE-binding properties of Ara h 3 were investigated using direct elisa and Western blotting with sera from peanut-allergic individuals. The basic subunits, and to a lesser extent the acidic subunits, bind IgE and may act as allergenic peptides. CONCLUSIONS: We conclude that peanut-derived Ara h 3, in contrast to earlier reported recombinant Ara h 3, resembles, to a large extent, the molecular organization typical for proteins from the glycinin family. Furthermore, posttranslational processing of Ara h 3 affects the IgE-binding properties and is therefore an essential subject of study for research on the allergenicity of Ara h 3.

Allergens↗

Identification and characterization of a second major peanut allergen, Ara h II, with use of the sera of patients with atopic dermatitis and positive peanut challenge.

Peanuts are frequently a cause of food hypersensitivity reactions in children. Serum from nine patients with atopic dermatitis and a positive double-blind, placebo-controlled, food challenge to peanut were used in the process of identification and purification of the peanut allergens. Identification of a second major peanut allergen was accomplished with use of various biochemical and molecular techniques. Anion exchange chromatography of the crude peanut extract produced several fractions that bound IgE from the serum of the patient pool with positive challenges. By measuring antipeanut specific IgE and by IgE-specific immunoblotting we have identified an allergic component that has two closely migrating bands with a mean molecular weight of 17 kd. Two-dimensional gel electrophoresis of this fraction revealed it to have a mean isoelectric point of 5.2. According to allergen nomenclature of the IUIS Subcommittee for Allergen Nomenclature this allergen is designated, Ara h II (Arachis hypogaea).

2S Albumins, Plant↗

Peanut ingestion increases rectal proliferation in individuals with mucosal expression of peanut lectin receptor.

BACKGROUND & AIMS: The Thomsen-Friedenreich blood group antigen (galactose beta 1,3-N-acetyl galactosamine alpha-) acts as an oncofetal antigen in the colonic epithelium, with low expression in normal adult epithelia but increasing to fetal levels of expression in hyperplasia or malignancy. Peanut lectin is one of the commonest dietary lectins that binds this antigen. The aim of this study was to determine whether peanut ingestion can alter rectal epithelial proliferation. METHODS: Thirty-six patients with normal colonic mucosa consumed 100 g of peanuts each day for 5 days. Rectal mitotic index was measured before and after ingestion, and changes in proliferation were correlated with immunohistochemical detection of lectin receptor expression by colonocytes and fecal lectin activity as measured by hemagglutination assay. RESULTS: Peanut ingestion caused a 41% increase in rectal mucosal proliferation in individuals with macroscopically normal mucosa who express TF antigen in their rectal mucosae (10 of 36 patients studied). The proliferative response correlated with fecal hemagglutinating activity, and peanut lectin could be shown immunohistochemically within the rectal mucosa. CONCLUSIONS: The common expression of galactose beta 1,3-N-acetyl galactosamine alpha- by hyperplastic and neoplastic epithelia may therefore be functionally important because it allows interaction with mitogenic dietary lectins. This could be an important mechanism for the association between diet and colorectal cancer.

Adult↗

Effects of methanol concentration and solvent:peanut ratio on extraction of aflatoxin from raw peanuts.

Aflatoxin B1 was extracted by a water slurry process using methanol concentrations of 55, 60, 65, and 70% in water and solvent:peanut ratios of 3, 4, 5, and 6 mL/g. Results failed to show that methanol concentration had an effect on amount of B1 extracted; however, the amount of B1 extracted increased with an increase in solvent:peanut ratio. Aflatoxin B1 was also extracted by the official AOAC method II, using methanol concentrations of 55, 60, 65, and 70% in water and solvent:peanut ratios of 2, 3, 4, and 5 mL/g. Results showed that the amount of B1 extracted increased with percent methanol at low solvent:peanut ratios but not at high ratios. Also, the amount of B1 extracted increased with solvent:peanut ratios at all methanol concentrations.

Aflatoxins↗

Investigation of the allergenicity of a refined peanut oil-containing topical dermatologic agent in persons who are sensitive to peanuts.

We determined if a topical oil containing 0.01% fluocinolone and refined peanut oil (Derma-Smoothe/FS topical oil), among other ingredients, included materials to which peanut-sensitive individuals were sensitized. No immediate (15-min) or delayed (72-h) skin test reactivity was demonstrated in any of the 14 subjects tested. These results suggest that this refined peanut oil-containing dermatologic preparation is safe to use, even in persons who are sensitive to peanuts.

Administration, Topical↗

Identification of a major peanut allergen, Ara h I, in patients with atopic dermatitis and positive peanut challenges.

Peanuts are among the most common causes of immediate hypersensitivity reactions to foods. Serum from nine patients with atopic dermatitis and a positive double-blind, placebo-controlled, food challenge to peanut were used to begin the process of identification and purification of the major peanut allergens. Identification of a major peanut allergen was accomplished by use of anion-exchange column chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, ELISA, thin-layer isoelectric focusing, and IgE-specific immunoblotting. Anion-exchange chromatography revealed several fractions that bound IgE from the serum of the challenge-positive patient pool. By measuring antipeanut-specific IgE in the ELISA and in IgE-specific immunoblotting, we identified an allergenic component with two Coomassie brilliant blue staining bands by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a mean molecular weight of 63.5 kd. Examination of this fraction by the IgE antipeanut ELISA with individual serum and by the ELISA-inhibition assay with pooled serum, we identified this fraction as a major allergen. Thin-layer isoelectric focusing and immunoblotting of this 63.5 kd fraction revealed it to have an isoelectric point of 4.55. Based on allergen nomenclature of the IUIS Subcommittee for Allergen Nomenclature, this allergen is designated, Ara h I (Arachis hypogaea).

Allergens↗

Aflatoxin production in six peanut (Arachis hypogaea L.) genotypes infected with Aspergillus flavus and Aspergillus parasiticus, isolated from peanut production areas of Cordoba, Argentina.

Aflatoxin contamination is one of the main factors affecting peanut seed quality. One of the strategies to decrease the risk of peanut aflatoxin contamination is the use of genotypes with resistance to Aspergillus infection. This laboratory study reports the resistance to Aspergillus infection and aflatoxin contamination of six peanut genotypes inoculated with 21 Aspergillus isolates obtained from the peanut production region of Cordoba, Argentina. The resistance was investigated in the seed coat and cotyledons of three resistant genotypes (J11, PI 337394, and PI 337409) and three breeding lines (Manfredi 68, Colorado Irradiado, and Florman INTA) developed at the Instituto Nacional de Tecnologia Agropecuaria (INTA), Manfredi Experimental Station, Cordoba, Argentina. Resistance to fungal colonization and aflatoxin contamination was found to be associated with seed coat integrity in the PI 337394, PI 337409, and J11 genotypes, whereas the INTA breeding lines such as Colorado Irradiado showed a moderate resistance and the Manfredi 68 and Florman INTA genotypes the least resistance. Furthermore, another type of resistance associated with cotyledons was found only in the PI 337394 genotype.

Aflatoxins↗

Peanut stripe potyvirus resistance in peanut (Arachis hypogaea L.) plants carrying viral coat protein gene sequences.

Peanut (Arachis hypogaea L.) lines exhibiting high levels of resistance to peanut stripe virus (PStV) were obtained following microprojectile bombardment of embryogenic callus derived from mature seeds. Fertile plants of the commercial cultivars Gajah and NC7 were regenerated following co-bombardment with the hygromycin resistance gene and one of two forms of the PStV coat protein (CP) gene, an untranslatable, full length sequence (CP2) or a translatable gene encoding a CP with an N-terminal truncation (CP4). High level resistance to PStV was observed for both transgenes when plants were challenged with the homologous virus isolate. The mechanism of resistance appears to be RNA-mediated, since plants carrying either the untranslatable CP2 or CP4 had no detectable protein expression, but were resistant or immune (no virus replication). Furthermore, highly resistant, but not susceptible CP2 T0 plants contained transgene-specific small RNAs. These plants now provide important germplasm for peanut breeding, particularly in countries where PStV is endemic and poses a major constraint to peanut production.

Arachis↗