Determination and characterization of cross-reacting allergens in latex, avocado, banana, and kiwi fruit

We previously suggested the presence of functionally atypical endothelin (ET) A receptors in the rabbit iris sphincter. Here, we further characterized the ET receptor by a radioligand-receptor binding study utilizing a membrane fraction of the rabbit iris. In addition, we functionally confirm the presence of an atypical ET(A) receptor in the iris dilator similar to that in the iris sphincter. In binding experiments, [125I]ET-1 was completely displaced by ET-3 in a biphasic fashion, but only partially by BQ-123 and ET(B) ligands. In the presence of RES-701, ET-3 and sarafotoxin (SRTX)-b completely displaced [125I]ET-1 in a monophasic fashion, but with shallow slopes. Moreover, ET-1, ET-3 and SRTX-b completely displaced [3H]BQ-123 with IC50 values of 0.8, 81 and 4.4 nM, respectively, but with slopes of ET-3 and SRTX-b being again shallow. In iris dilator muscles, ET-3 showed lower and SRTX-b showed higher contractile activities than ET-1. SRTX-c was inactive. BQ-123 more preferentially antagonized ET-3 and SRTX-b than ET-1, with the Schild plot slope of SRTX-b being shallow. Thus, functional experiments suggested the presence of atypical ET(A) receptors in the iris dilator similar to the iris sphincter. However, the binding experiments suggested the presence of rather typical ET(A)- and ET(B)-like receptors. Therefore, we apparently failed to show ET binding sites corresponding to functionally atypical ET(A) receptors.     

Update on occupational natural rubber latex allergy

Three beta-hydroxysteroid dehydrogenase/delta 5-delta 4-isomerase (3 beta HSD) deficiency is a form of congenital adrenal hyperplasia characterized by severe impairment of steroid biosynthesis in the adrenals and gonads. To better understand the molecular basis of the phenotypic heterogeneity found in 3 beta HSD deficiency, we analyzed the structure of type I and II 3 beta HSD genes in a female patient with nonsalt-losing 3 beta HSD deficiency diagnosed at puberty. We directly sequenced DNA fragments generated by polymerase chain reaction amplification of the four exons, the exon-intron boundaries, and the 5'-flanking regions of each gene. No mutation was detected in the type I 3 beta HSD gene, which is the predominant species expressed in the placenta and peripheral tissues. We detected a novel missense mutation, Y254D, in one allele of the patient's type II 3 beta HSD gene, which is the almost exclusive type expressed in the adrenals and gonads. The influence of the Y254D mutation on enzymatic activity was assessed by analyzing the recombinant mutant enzyme generated by site-directed mutagenesis after its transient expression in COS-1 monkey kidney cells. Recombinant mutant type II 3 beta HSD enzyme carrying the Y254D substitution exhibits no detectable activity with C21 delta 5-steroid pregnenolone or C19 delta 5-steroid dehydroepiandrosterone used as substrate. The absence of restriction fragment length polymorphism by Southern blot analysis and the finding that all of the amplified DNA fragments possess the expected length suggest the absence of deletions, duplications, or re-arrangements in the other allele. A putative second mutation could be located farther than 1427 basepairs upstream of the initiation codon, thus potentially affecting the normal expression of this gene or within intronic regions, generating an alternative aberrant splicing site. These are possibilities that remain to be elucidated. The present findings, which describe the novel missense mutation Y254D in the human type II 3 beta HSD gene, provide useful information on the structure-activity relationships of the 3 beta HSD superfamily.     

Prospective study of risk factors in natural rubber latex hypersensitivity

Five hundred sixty-nine subjects routinely underwent skin prick tests for latent sensitization to latex. The study of risk factors included skin tests to inhalant allergens, to diagnose atopy, and a questionnaire aimed at revealing frequent exposure to latex such as the wearing of gloves, multiple surgical procedures, or urinary catheterization. The subjects were categorized into five groups: group I, subjects with no risk factor (n = 272); group II, nonatopic subjects exposed to latex (n = 73); group III, atopic subjects not exposed (n = 180); group IV, exposed atopic subjects (n = 44); and group V, subjects with a history of intraoperative anaphylactic shock caused by latex (n = 13). Twenty-five subjects had spina bifida and were in either group II (14 subjects) or group IV (11 subjects). The questionnaire identified a probable allergy to latex in 18 subjects: 16 cases were confirmed by skin test, but responses were not informative in 23 patients who were sensitive to latex. Positive prick tests to latex were obtained in 0.37% of group I, 6.85% of group II, 9.44% of group III, and 36.36% of group IV. Of the children with spina bifida, 32% had positive skin test results. As risk factors, atopy and exposure were synergistic. We recommend predictive prick tests not only in children with spina bifida but also in any atopic subject or in any patient with a history of frequent exposure to latex. Latex could be considered a habitual allergen. The use of latex urinary catheters should be avoided in patients who are catheterized on a daily basis.     

The dental management of patients with natural rubber latex allergy

PURPOSE: The use of highly purified follicle-stimulating hormone (Metrodin-HP) was compared with that of a preparation containing follicle-stimulating hormone and luteinizing hormone (Pergonal) for production of superovulation in an IVF program. METHODS: We used the Oxford Fertility Unit database to identify patients undergoing their first cycle of IVF, using either Metrodin-HP or Pergonal. Patients were treated with a standardized drug protocol and were stratified by age and cause of infertility. Ovarian stimulation with either Metrodin-HP (Serono Laboratories) or human menopausal gonadotropin (hMG; Pergonal; Serono Laboratories) after pituitary desensitization commenced in the midluteal phase of the preceding cycle. Monitoring was performed by ultrasound and serum estradiol measurement prior to transvaginal oocyte recovery, followed by IVF and transfer of no more than three embryos. RESULTS: For Metrodin-HP versus Pergonal, the rates of egg retrieval (98 vs 94%), fertilization (89 vs 92%), clinical pregnancy (32.9 vs 23.4%), miscarriage (4.1 vs 4.5%), live birth (26 vs 18.5%), and ovarian hyperstimulation syndrome (5.5% vs 5.9%) were similar in both groups. The apparent increase in clinical pregnancy and live birth with Metrodin-HP did not reach statistical significance. The dosages of gonadotropins used were comparable. Estradiol levels measured on day 8 of stimulation were significantly lower in the Metrodin-HP group than in the Pergonal group, but the difference did not reach statistical significance on the day of hCG administration. Significantly more follicles (greater than 12 mm) were obtained in the Metrodin-HP group, but the numbers of eggs recovered and fertilized were similar in the two groups. CONCLUSIONS: These findings demonstrate that highly purified FSH (Metrodin-HP) is as effective and successful as hMG (Pergonal) for ovarian stimulation in a standard IVF regimen. Exogenous luteinizing hormone (LH) is not required for satisfactory ovarian stimulation in IVF. Measurement of estradiol may be less helpful in the monitoring of Metrodin-HP cycles, but the level reached on the day of hCG administration can still be used to predict, and hence avoid, ovarian hyperstimulation syndrome.     

Cross-reactivity between Ficus benjamina (weeping fig) and natural rubber latex

The efficacy of hydroxyzine and buspirone, controlled by placebo, was investigated in a double-blind, parallel group, multicentre study conducted in France and the UK. A total of 244 patients with generalised anxiety disorder in primary care was allocated randomly to treatments with hydroxyzine (12.5 mg morning and mid-day, 25 mg evening), buspirone (5 mg morning and mid-day, 10 mg evening) or placebo (three capsules/day) for 4 weeks, preceded by a 1-week single-blind placebo run-in and followed by 1-week single-blind placebo administration. Rating scales were applied on days -7,0,7,14, 12,28 and 35. Seventy percent of the patients were female, the average age was 41 +/- 11 years, and the mean Hamilton Anxiety Score at day 0 was 26.5 +/- 4.2. Only 31 of the 244 patients dropped out, but equally in the three groups. Intention-to-treat LOCF analyses on the primary variable showed a significant difference only between hydroxyzine and placebo with respect to improvement on the Hamilton Anxiety Scale (10.75 versus 7.23 points, respectively). Secondary variables such as CGI and self-ratings (HAD scale) showed both hydroxyzine and buspirone to be more efficacious than placebo. Thus, hydroxyzine is a useful treatment for GAD.     

Reinforcement of natural rubber latex with silica modified by cerium oxide: preparation and properties

Variable masses of nano cerium oxide(CeO__2) were added into nano silica(SiO__2) to prepare the well-dispersed SiO_2-CeO_2suspension(SiO_2-CeO_2), cetyltrimethyl ammonium bromide(CTAB) was used to adjust the compatibility of SiO_2-CeO_2 with rubber matrix, then SiO_2-CeO_2 modified by CTAB and curing formulas were mixed with fresh natural rubber(NR) latex to prepare NR/SiO_2-CeO_2 nanocomposites that contained 0–10 parts of CeO_2 by a new emulsion compounding method. The morphologies, cure characteristics, mechanical properties and thermal-oxidative stability of NR/SiO_2-CeO_2 nanocomposites were investigated. The results revealed that the presence of CeO_2 in NR/SiO_2-CeO_2 nanocomposites was favorable for enhancing the interaction between NR matrix and fillers, helped to get smaller SiO_2-CeO_2 particles with narrower particle size distribution, further improved the crosslink densities and mechanical properties of NR/SiO_2-CeO_2 nanocomposites vulcanizates. Meanwhile, the addition of CeO_2 increased the active energy at least 4.66%, obviously improved the thermal-oxidative aging-inhibiting properties of NR/SiO_2-CeO_2 nanocomposites. Additionally, nanocomposites containing CeO_2 promoted T g shift to high temperature direction, causing the nanocomposites featured higher tanδ at 0 oC and lower tanδ at 60 oC and exhibited comparable wet grip and lower rolling resistance when NR/SiO_2-CeO_2 nanocomposites were used in tire tread compound.     

Diagnosis of natural rubber latex allergy: multicenter latex skin testing efficacy study. Multicenter Latex Skin Testing Study Task Force

BACKGROUND: No characterized diagnostic natural rubber latex skin testing material is licensed for use in the United States. OBJECTIVE: We have conducted a multicenter clinical skin testing study to document the safety and diagnostic sensitivity and specificity of a candidate Hevea brasiliensis nonammoniated latex (NAL) extract. These data are intended to support the licensing of this reagent for the diagnosis of latex allergy in high-risk populations. METHODS: Three hundred twenty-four subjects (304 adults and 20 children) were classified by their clinical history as having latex allergy (LA group, 124 adults and 10 children) or having no latex allergy (NLA group, 180 adults and 10 children). All subjects provided blood samples and then received sequential puncture skin tests (PSTs) at 1, 100, or 1000 microg/mL protein with a bifurcated needle and NAL (Greer Laboratories) from Malaysian Hevea brasiliensis (clone 600) sap. A 2-stage glove provocation test was used to clarify latex allergy status of individuals with positive history/negative PST result and negative history/positive PST result mismatches. RESULTS: Twenty-four subjects (15%) originally designated as having LA on the basis of their initial clinical history were reclassified to the NLA group on the basis of a negative glove provocation test result. Of the 134 subjects with LA, 54 (40%) were highly sensitive to latex, with a positive PST result at 1 microg/mL NAL. The Greer NAL reagent produced a positive PST rate (sensitivity) of 95% and 99% in subjects with LA at 100 microg/mL and 1 mg/mL, respectively. The negative PST rate (specificity) in 190 subjects with a negative history with the NAL extract at 100 microg/mL and 1 mg/mL, was 100% and 96%, respectively. Immediately after the PST, mild systemic reactions (mainly pruritus) were recorded in 16.1 % of the adults in the LA group and 4.4% of the adults in the NLA group. No reactions required treatment with epinephrine. Only mild delayed reactions were observed in 9.6% (LA group) and 2.8% (NLA group) of subjects 24 to 48 hours after PST. Mean wheal and erythema diameters measured in the 10 children in the LA group with spina bifida at 100 microg/mL and 1 mg/mL were similar to those observed in the adults in the LA group, suggesting that children are not at increased risk for systemic reactions compared with adults. CONCLUSIONS: A suggestive clinical history is necessary but not sufficient for a definitive diagnosis of IgE-dependent latex allergy. These data support the safety and diagnostic efficacy of the Greer NAL, skin test reagent at 100 micro/mL and 1 mg/mL for confirmatory PSTs.     

消解乳化-火焰原子吸收光谱法测定胶乳中镁和锌

用消解 乳化法处理胶乳样品 ,即先用浓硝酸消解样品 ,以乙醇 甲基异丁基酮混合溶剂溶解消解产物 ,然后用乳化剂Tween -80乳化成乳浊液。建立了快速测定胶乳中镁、锌的FAAS法。以工作曲线法测定。对样品处理方法、消解产物的溶解性质、乳化剂的选择、试液与空白溶液粘度的一致性、线性范围、干扰及检出限进行了考察。测定结果与灰化法一致 ,相对标准偏差小于 3.2 % ,镁、锌的加标回收率分别为 95.85 %～ 10 0 .0 %和 99.0 %～ 10 3. 0 %。方法简便     

消解氨溶-火焰原子吸收光谱法测定胶乳中钠

用消解氨溶法处理胶乳样品 ,即先用浓硝酸消解样品 ,再用氨水溶解消解产物 ,建立了在氨性溶液中快速测定胶乳中钠的FAAS法。以硝酸钾溶液作为消电离剂 ,用工作曲线法测定。对样品处理方法、消解产物的溶解性质、线性范围、干扰及检出限进行了考察。测定结果的相对标准偏差 1.7% ,加标回收率 97.3 %～ 10 2.3 %。方法简便、快速、准确。     

Thermal degradation of epoxidized natural rubber in presence of neodymium stearate

The effect of neodymium stearate (NdSt) synthesized by saponification method on thermal degradation and thermo-oxidative degradation of expoxidized natural rubber with 25 mol.% epoxidation (ENR25) was investigated by thermogravimetric analysis (TGA), and the structure of ENR25 vulcanized with NdSt after thermo-oxidative decomposition was characterized using Fourier transform infared spectroscopy-attenuated total-reflectance (FTIR-ATR). The thermal degradation kinetic parameters of ENR25 with different loadings of NdSt were determined by Coats-Redfern method. The results showed that the thermal degradation of ENR25 in nitrogen was a one-step reaction regardless of NdSt content, whereas the thermo-oxidative degradation was a multiple-step reaction. The thermal and thermo-oxidative stability of the ENR25 vulcanizates with the addition of NdSt was higher than that of pure ENR25 vulcanizates. The ENR25 vulcanizates with the incorporation of 1 phr (per hundred parts of rubber) NdSt imparted the highest activation energy (E) of thermal and thermo-oxidative degradation. This could be attributed to the many unoccupied orbits in rare earth Nd, which could capture the free radicals and make the epoxide groups stable in the process of thermal and thermo-oxidative degradation for ENR25.     

Modification of a vinyl glove into a dental dam for patients sensitive to latex rubber

Transurethral microwave thermotherapy (TUMT) is a unique and promising method of treating benign prostatic hyperplasia. Clinical outcomes are related to thermal dose delivered. In 359 consecutive patients, strategies to increase thermal dose using the FDA-approved Prostasoft 2.0 delivered a mean of 148 kJ, which was almost 50 kJ more than the U.S. FDA trials. These strategies include careful preoperative patient teaching, exclusion of very small prostates, ketorolac, prewarming of the prostaprobe, antitorque of the rectal probe, use of urethral cooling adjustment during power ramping, and no manual power interruptions. Clinical outcomes improved without any significant adverse events. Peak urinary flow increased in 4 months by 5.5 mL/sec.     

Sensitivity to latex and other rubber substances--an important occupational risk for health personnel (case report)

Sensitization to latex and rubber additives has been acknowledged during the last 10 years as a major occupational health problem among health-care workers. In sensitized persons, respiratory and/or skin symptoms may be present. Pathophysiologic mechanisms of senzitisation involve allergic reactions types I and IV (Coombs and Gell). In this case report we described a female health-care worker with sensitization to latex and rubber additives simultaneously present on the skin and in the respiratory system, caused by wearing protective rubber gloves. The complex diagnostic procedure involved in determination of occupational allergic diseases is discussed.     

The global ethics of latex gloves: reflections on natural resource use in healthcare

The collagens produced by chick embryo chondrocytes cultured in alginate beads were investigated both biochemically and ultrastructurally. The cartilage phenotype is maintained for at least 14 days, as indicated by the production of the cartilage-specific collagens II, IX, and XI and the absence of collagen I. There were differences in the distributions of collagens among the three different compartments analyzed (cells and their associated matrix, further-removed matrix (released by alginate solubilization), and culture medium), with large amounts of collagen IX (mainly in proteoglycan form) in the culture medium. Inhibition of lysyl oxidase activity by beta-aminopropionitrile led to an overall decrease in collagen production. In contrast to the biochemical observations, collagen ultrastructure in the extracellular matrix of alginate cultures was not in the form of the expected 64-nm banded fibrils, but rather in the form of segment-long-spacing-like crystallites. This abnormal structure is likely to be a result of alginate disrupting normal assembly. We conclude that, in this system, the native fibrillar structure of the collagenous matrix is not essential for the maintenance of the differentiated phenotype of chondrocytes.     

Biodegradation of the composites based on polyethylene and sevilene with natural rubber

The mechanical properties, the water absorption, and the resistance to soil microrbiota of the composite films based on polyethylene and ethylene-vinyl acetate copolymers with additives of natural rubber are studied. The intensity of the biodegradation of the composites is shown to depend on both the mixture composition and the content of vinyl acetate units in a copolymer.     

Effect of neodymium stearate on cure and mechanical properties of epoxidized natural rubber

The effect of neodymium stearate (NdSt) on cure and mechanical properties of expoxidized natural rubber with 25 mol.% epoxida-tion (ENR25) was studied in the concentration range of 0 to 2 phr, and the relationship between structure and mechanical properties of ENR25 vulcanizates was also discussed. Neodymium sterate was synthesized by saponification of stearic acid with newly formed rare earth hydroxide in water medium, and the structure of NdSt was investigated by Fourier transform infrared spectroscopy (FTIR). Crosslinking den-sity of vulcanized natural rubber was studied by equilibrium swelling method. The results indicated that the interaction force between carbox-ylic ion of NdSt prepared in the lab and Nd ion was mainly ionic bond through FTIR analysis. NdSt could accelerate the vulcanization of ENR25 and influence the network structure of ENR25 vulcanizates. The incorporation of 1 phr NdSt for ENR25 vulcanizates showed the op-timal aging resistnce.     

Issues and answers in latex sensitivity

Latex sensitivity is a problem for many healthcare professionals. Latex is found in numerous items that a healthcare professional uses on a daily basis, including gloves, tapes, bandages, and catheters. Latex sensitivity can appear as a mild, localized contact reaction, or, in extreme cases, have more sever, systemic effects. Latex not only has the potential to affect a healthcare professional's career, but it can also adversely affect the healthcare professional's life. Several agencies have responded to the increased prevalence of latex-related illnesses, including the Food and Drug Administration and the Centers for Disease Control and Prevention. Lack of a national database and l lack of a government policy mandating the labeling of latex-containing products are just some of the problems that hinder latex research. While there are many unanswered questions regarding latex sensitivity, there are several steps that a healthcare professional can take to protect himself or herself from latex. These include: proper documentation and treatment, preventive measures such as wearing a medical alert tag or bracelet, finding and using latex alternatives in the workplace, and setting up official latex policies within their facilities.     

Masked and labelled food allergens

Several food proteins are used as food additives or may be contained in foods as contaminants. These masked allergens are at high risk of inducing severe clinical reactions: acute asthma, laryngeal angioedema, anaphylactic shock or even death. The present regulation requires labelling only if the level of food ingredients is superior to 25% of the final product. Several immunologic methods can detect low levels of proteins, equal or inferior to 2%. However a level of 1% or less may be noxious, suggesting a need for a specific line of food products which could be guaranteed free of ... and which might be recommended to patients with food allergy.