A novel method for rapid and quantitative detection of bisphenol A in urine

Bisphenol A (BPA) is classified as an endocrine disruptor (ED) and it can interact with variety of hormone receptors leading to hormonal disruption and increased risk of various adverse health effects. Reducing human exposure to BPA is one of the main challenges of public health, as it is constantly present in daily life. A low-cost and commonly applied method to enable determination of BPA in the patient's body has yet to be developed. Currently available techniques are expensive, time-consuming, and require access to highly equipped analytical chemistry laboratories. Here we describe a fast and cheap engineered lateral flow assay of our design, to detect of BPA in urine samples. The technology not only provides an opportunity to perform rapid medical diagnostics without the need for an access to the central laboratory but also a means for self-diagnosis by the patient. The addition of β-glucuronidase improves the sensitivity of detection as it releases the free BPA from glucuronide complexes in urine. This invention may become a demonstrated analytical means for lowering human exposure to BPA and probably also to other EDs and consequently, may be useful in decrease of the risk for several lifestyle diseases.

Sex-associated protective effect of early bisphenol-A exposure during enteric infection with Trichinella spiralis in mice

Bisphenol A (BPA) is an endocrine disruptor compound with estrogenic activity, possessing affinity for both nuclear (ERα and ERβ) and membrane estrogen receptors. The main source of BPA exposure comes from the contamination of food and water by plastic storage containers or disposable bottles, among others, in which case BPA is easily ingested. Exposure to BPA during early pregnancy leads to lifelong effects; however, its effect on the immune system has not been fully studied. Since endocrine and immune systems interact in a bidirectional manner, the disruption of the former may cause permanent alterations of the latter, thus affecting a future anti-parasitic response. In this study, neonate BALB/c mice were exposed to a single dose of BPA (250 μg/kg); once sexual maturity was reached, they were orally infected with Trichinella spiralis (T. spiralis). The analyses performed after 5 days of infection revealed a decreased parasitic load in the duodenum of mice in the BPA-treated group. Flow cytometry analyses also revealed changes in the immune cell subpopulations of the infected animals when compared to the BPA-treated group. RT-PCR analyses of duodenum samples showed an increased expression of TNF-α, IFN-γ, IL-4, IL-5, and IL-9 in the BPA-treated group. These findings show a new aspect whereby early-life exposure to BPA contributes to the protection against T. spiralis by modulating the anti-parasitic immune response.

Universal and reusable hapten/antibody-mediated portable optofluidic immunosensing platform for rapid on-site detection of pathogens

A universal and reusable hapten-antibody-mediated portable optofluidic immunosensing platform (OIP) was developed for rapid on-site detection of pathogens. By using Escherichia coli O157:H7 (E. coli O157:H7) and bisphenol A-Bovine serum albumin (BPA-BSA)/anti-BPA antibody as a model pathogen and a mediated hapten-antibody, respectively, a novel immunoassay mechanism was proposed to detect pathogens. The BPA-BSA-modified immunosensor and E. coli O157:H7 were initially saturated with anti-BPA antibodies (mouse IgG) and anti-E. coli O157:H7 antibodies (mouse IgG), respectively. Then, the fluorescence-labeled secondary antibodies (goat anti-mouse IgG antibody) were incubated with E. coli O157:H7 with their antibodies. Next, the mixture was introduced into the immunosensor surface bound to the anti-BPA antibodies. A high concentration of E. coli O157:H7 in the sample reduced the number of fluorescence-labeled secondary antibodies bound to the immunosensor surface, thus resulting in the detection of low fluorescence signals. Under optimized conditions, the hapten-antibody-mediated OIP system exhibited a detection limit of 8 cfu/mL E. coli O157:H7 after concentrating 100 times by using centrifugation, and a test cycle, including prereaction, detection, and regeneration, was less than 1 h. The robustness of the hapten-carrier protein-modified immunosensor surface allowed multiple pathogen immunoassays. The proposed strategy demonstrated good recovery, precision, and accuracy through the evaluation of the spiked water samples. We expect that the new platform can be readily used for the detection of other pathogens in a variety of application fields ranging from environmental monitoring and food safety to medical diagnosis.

The Association of Serum Bisphenol A with Thyroid Autoimmunity

Introduction: Data on the association of bisphenol A (BPA) exposure and autoimmunity in humans is unclear. Objective: To elucidate the influence of BPA on thyroid autoimmunity, in the present study we assessed the association between serum BPA and thyroid autoantibodies. Methods: Serum samples from 2361 subjects, aged ≥15 years, from the Thai 4th National Health Examination Survey were measured for BPA, antithyroglobulin (TgAb), antithyroperoxidase (TPOAb) and antithyrotrophin receptor (TRAb) antibodies. Results: The proportion of subjects positive for TgAb, TPOAb and TRAb were 11.1%, 14.9% and 1.9%, respectively. With regard to BPA, 51.9% had serum BPA levels exceeding the detection limit of the assay (0.3). There was a significant increasing trend for subjects with TgAb (p < 0.05) and TPOAb (p < 0.001) positivity as BPA quartiles increased, particularly in the highest quartile. In contrast, no relationship between BPA quartiles and TRAb was found. Logistic regression analysis showed that age, gender and BPA quartiles were determinants of TPOAb or TgAb positivity, independent of BMI. However, only the association between BPA and TPOAb positivity was consistent in both men and women. Conclusions: BPA was independently associated with TPOAb positivity. However, its mechanism related to TPOAb positivity, subsequently leading to autoimmune thyroid disease, needs further investigation.

Competitive immunoassay for analysis of bisphenol A in children's sera using a specific antibody

Bisphenol A (BPA) has been reported as a potential estrogenic substance that could affect human health and reproduction. In this study, a monoclonal antibody (Mab) against BPA was produced after the immunization of Balb/c mice with a conjugate of 4,4-bis (4-hydroxyphenyl) valeric acid coupling with keyhole limpet hemocyanin (BVA-KLH). The obtained Mab showed higher affinity against BPA and lower cross-reactivity toward 4,4'-sulfonyldiphenol, diphenolic acid, hydroquinone, salicylic acid, and other common phenolic compounds. Basing on the Mab, an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) was developed. Under the optimal conditions, the limit of detection (LOD) was found to be 0.1 ng mL(-1) with the linear working range of 0.45-10.56 ng mL(-1). After sample extraction, the fortified serum samples were detected with intra- and inter-assay recovery ranges of 81.2-92.9 and 84.4-94.4 %, respectively. Then, 100 children's sera were screened by ic-ELISA. The result showed that 54 % of the serum samples were BPA-positive. The positive samples were purified by immuno-affinity column (IAC) and further confirmed by high-performance liquid chromatography (HPLC) with fluorescence detector measured at λ ex/λ em 228/310 nm in acetonitrile-water solution (v:v, 40:60). The analysis of the unknown samples showed that ic-ELISA agreed well with the HPLC results. It also revealed that the ELISA developed here could be a useful tool for screening BPA in children's sera before the validation of HPLC.

A novel elicitor identified from Magnaporthe oryzae triggers defense responses in tobacco and rice

KEY MESSAGE

Our studies indicate a potential important elicitor candidate which can aid in the fight against a worldwide disease, rice blast. In this study, we report the purification, identification, characterization, and gene cloning of a novel hypersensitive response-inducing protein elicitor (MoHrip2) secreted from an important pathogenic fungus, Magnaporthe oryzae. The protein fraction was isolated from the culture filtrate of M. oryzae and identified by de novo sequencing. The elicitor-encoding gene mohrip2 was cloned following sequence comparison and PCR amplification. This 459-bp gene encodes a 152-residue polypeptide that contains an 18-residue signal peptide and exhibits a pI of 4.72 and an apparent molecular mass of 16 kDa. The hypothetical protein, MoHrip2, was expressed in Escherichia coli, and both the recombinant and the endogenous protein caused necrotic lesions in tobacco leaves. In addition to phenolic compound deposition and alkalization of the extracellular medium, MoHrip2 also induced hydrogen peroxide production and nitric oxide accumulation in tobacco cells. Moreover, rice seedlings treated with MoHrip2 exhibited pronounced resistance to M. oryzae compared with control seedlings.

Mac1 Positive Cells Are Required for Enhancement of Splenocytes Proliferation Caused by Bisphenol A

We examined the effects of bisphenol A (BPA) on immune cells and it was shown that BPA upregulated the proliferation of murine splenocytes stimulated with Concanavalin A (ConA). The upregulating effects of BPA were removed with depleting Mac1+ cells from the splenocytes. This study provides evidence for the first time that Mac1+ cells were required for enhancement of splenocytes proliferation caused by bisphenol A.

Environmental alkylphenols modulate cytokine expression in plasmacytoid dendritic cells

Background

Alkylphenols, such as nonylphenol (NP) and 4-octylphenol (4-OP), have the potential to disturb immune system due to their weak estrogen-like activity, an effect with potential serious public health impact due to the worldwide distribution of these substances. Plasmacytoid dendritic cells (PDCs) can secrete large amounts of type I IFNs and are critical in immune regulation. However, there has been limited study about the influence of alkylphenols on the function of pDCs.

Objective

The aim of this study was to examine the effect of alkylphenols on pDC functions in vitro and in vivo and then further explored the involved signaling pathways and epigenetic changes.

Methods

Circulating pDCs from human peripheral blood mononuclear cells were treated with alkylphenols with or without CpG stimulation. Alkylphenol-associated cytokine responses, signaling events, histone modifications and viral activity were further examined. In NP-exposed mice, the effect of NP on splenic pDC function and allergic lung inflammation were also assessed.

Results

The results showed that NP increased the expression of TNF-α, but suppressed IL-10 production in the range of physiological doses, concomitant with activation of the MKK3/6-p38 signaling pathway and enhanced levels of acetylated histone 3 as well as histone 4 at the TNFA gene locus. Further, in CpG-stimulated pDCs, NP suppressed type I IFNs production, associated with down-regulation of IRF-7 and MKK1/2-ERK-Elk-1 pathways and led to the impaired anti-enterovirus 71 activity in vitro. Additionally, splenic pDCs from NP-exposed mice showed similar cytokine changes upon CpG stimulation under conditions relevant to route and level of exposure in humans. NP treatment also enhanced allergic lung inflammation in vivo.

Conclusion

Alkylphenols may influence pDCs’ functions via their abilities to induce expression of a pro-inflammatory cytokine, TNF-α, and to suppress regulatory cytokines, including IL-10, IFN-α and IFN-β, suggesting the potential impact of endocrine disrupting chemicals on immune regulation.

Polyphenols, inflammation, and cardiovascular disease

Polyphenols are compounds found in foods such as tea, coffee, cocoa, olive oil, and red wine and have been studied to determine if their intake may modify cardiovascular disease (CVD) risk. Historically, biologic actions of polyphenols have been attributed to antioxidant activities, but recent evidence suggests that immunomodulatory and vasodilatory properties of polyphenols may also contribute to CVD risk reduction. These properties will be discussed, and recent epidemiological evidence and intervention trials will be reviewed. Further identification of polyphenols in foods and accurate assessment of exposures through measurement of biomarkers (i.e., polyphenol metabolites) could provide the needed impetus to examine the impact of polyphenol-rich foods on CVD intermediate outcomes (especially those signifying chronic inflammation) and hard endpoints among high risk patients. Although we have mechanistic insight into how polyphenols may function in CVD risk reduction, further research is needed before definitive recommendations for consumption can be made.

Dichlorophenol-containing pesticides and allergies: results from the US National Health and Nutrition Examination Survey 2005-2006

BACKGROUND

Epidemiologic studies support the hypothesis that reduced microbial exposure in westernized societies promotes atopy. Dichlorophenols are widely used as pesticides and for chlorination of water. They have a strong bactericidal effect that could affect microflora in the environment. However, it is unknown whether their use is associated with a higher prevalence of allergies.

OBJECTIVE

To test the association between exposure to environmental pesticides represented by dichlorophenols and allergic sensitization measured by allergen-specific serum IgE levels in a US nationally representative sample of 2,211 persons 6 years and older in the National Health and Nutrition Examination Survey 2005-2006.

METHODS

Exposure to dichlorophenols was defined as high if their levels in urine were present at the 75th percentile and above. Association of the high exposure to dichlorophenols with sensitization to food and environmental allergens was assessed in logistic regression models after adjustment for sample weights and potential confounders.

RESULTS

Sensitizations to 1 or more food allergens were more common in those with exposure to 2 dichlorophenol metabolites. After multivariable adjustment, urine dichlorophenol levels at the 75th percentile and above were associated with the presence of sensitization to foods (odds ratio, 1.8; 95% confidence interval, 1.2-2.5; P = .003). No significant association was found between dichlorophenol exposure and sensitization to aeroallergens alone.

CONCLUSION

High urine levels of dichlorophenols are associated with the presence of sensitization to foods in a US population. Excessive use of dichlorophenols may contribute to the increasing incidence of food allergies in westernized societies.

Fetal exposure to bisphenol A as a risk factor for the development of childhood asthma: an animal model study

BACKGROUND

The prevalence of asthma in industrialized countries has been increasing dramatically and asthma is now the most common chronic disease of children in the United States. The rapidity of the increase strongly suggests that changes in environmental exposures are the likely cause of this epidemic. Further, the early onset of allergic manifestations suggests that these exposures may act on the prenatal development of the immune system. We have focused on the potential effects of bisphenol A (BPA), a chemical pollutant with one of the largest productions, on the development of childhood asthma. We have reported that perinatal BPA exposure promotes the development of allergic asthma in a mouse model. The current study was designed to identify a critical period of BPA exposure and to begin elucidating the mechanisms for this susceptibility.

METHODS

Female BALB/c mice received 10 micro g/ml BPA in their drinking water from one week before pregnancy until the end of the study. Some of the pups were transferred in the first 48 h of life from their BPA-loaded mother to an unexposed mother, or vice versa. Half of the pups were sensitized with a low dose of the experimental allergen ovalbumin (OVA), the rest received PBS as an unsensitized controls. On day 22, the pups were challenged by inhalations of ovalbumin or PBS followed by quantification of eosinophils in and hyperreactivity of their airways, major indicators of experimental asthma in this classical mouse model. Hepatic expression of two isoforms of UDP-glucuronosyltransferase (Ugt) was quantified by quantitative RT-PCR at various ages.

RESULTS

Pups exposed to BPA in utero and through breast milk, or in utero only, displayed an asthma phenotype in response to their "suboptimal" allergic sensitization, whereas, pups only exposed to BPA postnatally from breast milk, did not. The expression of Ugt2b1, an isoform related to BPA clearance in rats, was not detectable in mouse fetuses and newborn pups, but increased by day 5 and approached adult levels by day 25.

CONCLUSIONS

Prenatal exposures that produce environmentally relevant burdens of BPA, followed by postnatal allergic sensitization and challenges, promote the development of experimental allergic asthma. Delayed expression of BPA-metabolizing enzymes may explain, at least in part, the enhanced fetal susceptibility to this common environmental contaminant.

Maternal bisphenol a exposure promotes the development of experimental asthma in mouse pups

BACKGROUND

We recently reported that various environmental estrogens induce mast cell degranulation and enhance IgE-mediated release of allergic mediators in vitro.

OBJECTIVES

We hypothesized that environmental estrogens would enhance allergic sensitization as well as bronchial inflammation and responsiveness. To test this hypothesis, we exposed fetal and neonatal mice to the common environmental estrogen bisphenol A (BPA) via maternal loading and assessed the pups' response to allergic sensitization and bronchial challenge.

METHODS

Female BALB/c mice received 10 microg/mL BPA in their drinking water from 1 week before impregnation to the end of the study. Neonatal mice were given a single 5 microg intraperitoneal dose of ovalbumin (OVA) with aluminum hydroxide on postnatal day 4 and 3% OVA by nebulization for 10 min on days 13, 14, and 15. Forty-eight hours after the last nebulization, we assessed serum IgE antibodies to OVA by enzyme-linked immunosorbent assay (ELISA) and airway inflammation and hyperresponsiveness by enumerating eosinophils in bronchoalveolar lavage fluid, whole-body barometric plethysmography, and a forced oscillation technique.

RESULTS

Neonates from BPA-exposed mothers responded to this "suboptimal" sensitization with higher serum IgE anti-OVA concentrations compared with those from unexposed mothers (p < 0.05), and eosinophilic inflammation in their airways was significantly greater. Airway responsiveness of the OVA-sensitized neonates from BPA-treated mothers was enhanced compared with those from unexposed mothers (p < 0.05).

CONCLUSIONS

Perinatal exposure to BPA enhances allergic sensitization and bronchial inflammation and responsiveness in a susceptible animal model of asthma.

A scFv antibody-based immunoaffinity chromatography column for clean-up of bisphenol A-contaminated water samples

This is a report on the development of immunoaffinity chromatography using a column of silica gel with an immobilized single-chain variable fragment (scFv) antibody specific to bisphenol A (BPA) for cleanup of BPA-contaminated water samples. The BBA-2187 scFv antibody specific to BPA was purified from the periplasmic fractions of the recombinant Escherichia coli. After a sample of BPA-contaminated river water was applied to the immunoaffinity column, the background signal intensity observed in high-performance liquid chromatography (HPLC) analysis of the eluates was markedly lower than that observed in HPLC analysis of the eluates from an Oasis HLB cartridge treated with the same sample. The immunoaffinity column efficiently concentrated BPA from actual river water samples with different matrices. Our results demonstrate that the immunoaffinity column with immobilized BBA-2187 scFv antibody is efficient for the cleanup of BPA-contaminated water samples from different sources.

[Study on spectral and immune identification of artificial antigen of bisphenol A]

Bisphenol A(BPA) is able to mimic the effects of endogenous hormones and it influences the central nervous system in human being. In recent years, BPA has largely arisen because it is released into our environment from many kinds of the polycarbonate plastics and epoxy resins of food cans. Because trace residual amount of BPA might be harmful to human being, many instrument analysis methods have been developed for the determination of BPA. But these instrument analysis methods require complicated pre-treatment steps and do not suit rapid processing of multiple samples. Gold-labeled immunochromatography assay method can provide in situ monitoring of trace BPA in ground-water and drinking water. In order to build the simple and fast gold-labeled immunochromatography assay method, it is necessary to synthesize and identify artificial antigen of BPA firstly. The modified BPA was conjugated with the carrier of bovine serum albumin (BSA) by EDC * HCl, after dialyzed, the synthesized artificial antigen of BPA was lyophilized, and then stored at -20 degrees C. Three methods such as UV and IR spectra scanning and immunoassay were used to determine whether artificial antigen of BPA had been synthesized. The results showed that UV spectrum of artificial antigen of BPA has one absorbance band at 278 nanometers (nm) which is the characteristic absorbance band of the carrier of bovine serum albumin, and another absorbance band at 226 nm which is the characteristic absorbance band of BPA. The IR spectrum absorbance bands of bovine serum albumin and BPA appeared on the IR spectrum graph of artificial antigen of BPA, moreover, shrinked vibration bands at 1 000-1 300 cm(-1) showed that a C-N bond was produced and suggested that the modified BPA and BSA had been linked. The antibody of anti-BPA was raised in sera of immunized Balb/c mice by indirect competitive ELISA. So the above results showed that the artificial antigen of BPA was synthesized successfully. The artificial antigen of BPA can be used to develop monoclonal antibody of anti-BPA and also to prepare gold-labeled immunochromatography assay method for in situ monitoring of BPA in the future.

Immunostimulating activity of a crude polysaccharide derived from green tea (Camellia sinensis) extract

Green tea extract is well-known to reduce the risk of a variety of diseases. Here, we investigated the immunostimulating activity of tea polysaccharide (TPS), one of the main components in green tea extract. The water extracts from mature or immature tea leaves were precipitated by using ethanol at room temperature. The sediment was washed with ethanol and acetone alternately and then dried. We used the phagocytic activity of macrophage-like cells as an indicator of immune function activation. Chemical components were analyzed by HPLC. The immunostimulating activity of TPS from immature leaves extract was higher than that of TPS from mature leaves, and its activities were dependent on the content of strictinin in the leaf extract. Futhermore, a mixture of catechin and TPS that removed polyphenols did not increase the immunostimulating activity. These results suggest that the catechin-polysaccharide complex is a very important molecule in the immunomodulating activity of tea extracts.

Immune response to ovalbumin following bisphenol A administration in mice fed with a low level of dietary protein

BACKGROUND AND PURPOSE

We have previously shown that bisphenol A (BPA) augments T-helper (Th) 1 activity with no significant effects on an established oral tolerance to ovalbumin (OVA) in mice fed with a normal protein diet. The present study aimed to examine the effect of BPA on the immune response in a mouse model maintained on a very low protein diet (5% casein).

METHODS

Mice were fed on a 5% protein diet, together with either OVA (OVA-fed) or water (water-fed), immunized intraperitoneally with OVA at 3-week intervals and administered BPA between the 2 immunizations. A week after the last immunization, animals were sacrificed and examined by enzyme-linked immunosorbent assay for serum titers of total immunoglobulin E (IgE), OVA-specific IgE, immunoglobulin G (IgG), IgG1, IgG2a, and the production of interferon-gamma, interleukin (IL)-4, and IL-12.

RESULTS

In both BPA-treated and non-treated animals, OVA feeding resulted in lower titers of total and OVA-specific IgE, and OVA-specific IgG (p<0.05). There were higher levels of interferon-gamma (p<0.05), IL-4, and IL-12 (p<0.05) in animals with OVA tolerance following BPA treatment. However, IL-12 production was augmented only in BPA-treated water-fed animals (p<0.01).

CONCLUSION

BPA administration in mice fed with a low level of dietary protein augmented Th1 cytokines more profoundly in the animals with OVA tolerance than in the non-tolerant animals.

An impedimetric immunosensor for the label-free detection of bisphenol A

Label-free detection of bisphenol A based on the impedance measurement was achieved with an impedimetric immunosensor. The immunosensor was fabricated by the covalent bond formation between a polyclonal antibody and a carboxylic acid group functionalized onto a nano-particle comprised conducting polymer. By using a commercial reagent 4,4-bis(4-hydroxyphenyl) valeric acid (BHPVA), which has an analogous structure of BPA, we have prepared the antigen through the conjugation of BHPVA with bovine serum albumin (BSA) and then produced a specific polyclonal antibody. The immobilization of antibody and the interaction between antibody and antigen were studied using quartz crystal microbalance (QCM) and electrochemical impedance spectroscopic (EIS) techniques. The impedance and mass changes due to the specific immuno-interaction at the sensor surface were utilized to detect antigen and bisphenol A (BPA). The immunosensor showed specific recognition of BPA with less interference than 4.5% from other common phenolic compounds. Under an optimized condition, the linear dynamic range of BPA detection was between 1 and 100 ng/ml. The detection limit of bisphenol A was determined to be 0.3+/-0.07 ng/ml. The proposed immunosensor was applied to a human serum sample and the BPA concentration was determined by the standard addition method.

Immunomodulatory effects of mono-, di-, and trimethylphenols in mice

The relationship of air pollutants with the increasing prevalence of allergic diseases is a matter of concern in developed countries. In this study, the immunomodulatory effects of mono-, di-, and trimethylphenols in mice were examined as regards two aspects. First, whether or not these chemicals act as sensitizers was evaluated by local lymph node assay. Of the 13 methylphenols tested, three dimethylphenol isomers (2,4-DMP, 2,5-DMP, and 3,4-DMP) were found to induce auricular lymphocyte proliferation after dermal application on both ears of mice. Cytokine production patterns in the supernatants of cultured auricular lymphocytes from mice showed these methylphenols to be contact sensitizers. Second, the effects of methylphenols on cytokine production profiles were examined using cultured splenocytes from immunologically naive mice. Under subtoxic conditions, eight methylphenols inhibited interferon-gamma (IFN-gamma) production significantly, while the effect on intreluekin-4 (IL-4) production was moderate, resulting in higher IL-4/IFN-gamma ratios in all of the tested chemicals, with the most prominent effect shown by 2,6-DMP. These results suggest that several methylphenols, especially dimethylphenol isomers, have potencies that affect the immune system, being immunogens themselves or modulators of the Th1/Th2 cytokine balance.

Piezoelectric immunosensor for bisphenol A based on signal enhancing step with 2-methacrolyloxyethyl phosphorylcholine polymeric nanoparticle

An immunoassay in which BPA competed with a BPA-horseradish peroxidase conjugate for binding to anti-BPA antibodies, coupled to a piezoelectric (PZ) immunosensor, was able to detect 0.1 ng mL(-1) BPA. To enhance the sensitivity of the assay, we tested nanoparticles approximately 200 nm in diameter, coupled to anti-BPA antibodies, to increase the mass change on the surface of the immunosensor and thereby increase the frequency shift detected. This second step, using nanoparticles coated with anti-BPA antibodies, improved the sensitivity of the assay by approximately eight times at BPA concentrations below 10 ng mL(-1). Field emission-scanning electron microscopy (FE-SEM) showed that polymeric 2-methacrolyloxyethyl phosphorylcholine (MPC) nanoparticles coupled to antibodies remained monodisperse on the surface of the immunosensor and therefore produced stable signals in the immunosensors. Since the frequency shift detected in the assay mainly originated from the mass change on the surface of the PZ crystal, the colloidal stability of the antibody-conjugated particles used in the enhancement step played an extremely important role in achieving a stable and highly sensitive signal.

Analysis of bisphenol A in natural waters by means of an optical immunosensor

This work describes a very simple, fast and sensitive method based on the use of the optical immunosensor "RIver ANAlyser" (RIANA) to the determination of bisphenol A in a waters. RIANA is based on a rapid solid-phase indirect inhibition immunoassay that takes place at an optical transducer chip chemically modified with an analyte derivative. Fluorescence produced by labelled antibodies bound to the transducer is detected by photodiodes and can be correlated with the analyte concentration. The sensor surface can be regenerated thus allowing the performance of several measurements (around 300) with the same transducer. Each test cycle, including one regeneration step, is accomplished in 15 min. The detection limit achieved in the direct determination of bisphenol A in water with this system was 0.014 microg/L. Satisfactory repeatability, with relative standard deviations (RSD) ranging between 1.48% and 6.93% were obtained. The immunosensor method developed was applied to the monitoring of bisphenol A in various types of water collected in a waterworks (from the river water source to the finished drinking water) and validated against the results obtained in the same approach by a more traditional method, based on solid-phase extraction followed by liquid chromatography-mass spectrometry. Results obtained by both techniques were in general good agreement (considering the typical overestimation bias of immunoassays), and served to prove the satisfactory removal efficiency of the overall purification process applied in the waterworks and, in particular, of the sand filtration step.

Synthesis of haptens for development of antibodies to alkylphenols and evaluation and optimization of a selected antibody for ELISA development

The development of an enzyme-linked immunosorbent assay (ELISA) based on polyclonal antibodies for a class of endocrine disrupting compounds, 4-nonylphenol, is described. The parent molecule was derivatized at the ortho position of the free phenolic hydroxyl group to obtain the hapten, NP1, and it was conjugated with keyhole limpet hemocyanin, which was used as an immunogen. Four antisera were generated and screened against three coating antigens. The most sensitive ELISA from the screening tests (antiserum NP03As, 1/1000, and coating antigen NP1-BSA, 1 microg/mL) was further optimized and characterized. The influence of various physicochemical factors (organic solvent, pH, ion strength) was investigated. Methanol as the additive organic solvent was found to be the best organic solvent for the ELISA, with optimal sensitivity observed at a concentration of 5%. The ELISA parameters were changed at more acidic or basic pH values, whereas higher ionic strengths strongly suppressed the I(50) value and the maximum absorbance. The most sensitive ELISA for 4-nonylphenol exhibited an I(50) value of 38.6 +/- 5.5 microg/L, with a dynamic range from 12 to 350 microg/L, and the lower limit of detection was 7.7 +/- 1.3 microg/L. The optimized ELISA displayed no significant cross-reaction against the parent compounds, nonylphenol ethoxylates, degradation products, carboxylates, and bisphenol A, except in 4-octylphenol.

Polyphenolic antioxidants enhance IgE production

Epidemiological data showed that total IgE and IL-4 levels in cigarette smokers were elevated, comparable to those in the asthmatics. The etiological agent(s) elevating IgE production are not clear. We evaluate whether tobacco polyphenols potentiate IgE production in a rodent model. Mice were fed with rutin or CGA in drinking water during antigen sensitization, followed by antigenic challenge i.p. in alum. CGA and rutin were also delivered in a bolus intraperitoneally or intranasally along with antigens during immunization. Antigen-specific IgE and IgG responses were measured. Enhancement of total IgE responses via i.p. and drinking routes can be achieved at concentrations as low as 0.1% CGA. Furthermore, IgG1 responses but not IgG2a and IgG2b were augmented, indicating a Th2 type of response by CGA. Moreover, both antigen-specific and serum IgE production can be achieved when CGA and antigenic challenges were delivered intranasally in the absence of alum. In contrast, nicotine does not enhance antigen-specific IgE production, and only marginally affects serum IgE levels. The more polarized Th2 development in CGA-treated mice may account for enhancement of both antigen-specific and total IgE responses. High levels of IL-4 but not IFN-gamma or IL-12, were observed in antigen-challenged mesenteric lymph nodes (MLN) cultures from CGA-treated mice. In contrast, significant levels of IL-4, IL-12, and IFN-gamma were observed in antigen-challenged cultures from nicotine-treated mice. This study shows that tobacco polyphenols, CGA and rutin potentiated IgE production in vivo. Polyphenolic antioxidants enhance Th2 development. We propose that IgE production and T cell dichotomy may be critically influenced by the redox microenvironment. Enhanced Th2 development and IgE production henceforth may counteract more severe Th1-mediated tissue damage triggered by environmental oxidative stress.

[Immunoenzyme analysis of non-ionic surfactants in water]

The approaches for high sensitive and specific determination of nonylphenol (NP) with the help of immune enzymatic (ELISA) method have been developed. The process of preparation of conjugates of NP with proteins, antiserum obtaining, purification of immunoglobulin (Ig) fractions and study of specificity of the obtained antibodies were described in detail. It was shown that the antiserum and total Ig fraction do not differ in respect of specificity and binding abilities. The developed algorithm of ELISA method fulfillment is able to provide NP revealing with the sensitivity in the range of 20-50 ng/ml and working controlled concentrations--from 20-50 to 1000 ng/ml.

Apnea and bradycardia due to anaphylaxis to tobacco glycoprotein in the infant rabbit

Prenatal and postnatal exposure to cigarette smoke is associated with an increased incidence of the sudden infant death syndrome, although the cause(s) for this is unknown. Tobacco glycoprotein (TGP), a group of proteins purified from cured tobacco leaves and present in cigarette smoke, have been shown to cause anaphylaxis in excised hearts and lungs of adult rabbits that were neonatally sensitized to TGP and later rechallenged. We sought to determine whether anaphylaxis occurred in live infant rabbits who were neonatally sensitized to TGP. At the age of 1 day, 12 animals were sensitized to TGP (0.1mg in 0.25 cc alum) via intraperitoneal injection (i.p.i.) followed by a booster ipi at the age of 30 days (TGP-S). Seven animals received i.p.i. of antigen-free alum only (controls). All animals underwent an intravenous TGP challenge at age 42+/-2 days. Heart rate (HR) and respiratory rate (RR) were recorded for 2 min prior to and 5 min after the challenge. Baseline HR (approximately 260) and RR (approximately 120) were similar in all animals. Seven TGP-S animals developed apnea (1.9-4.7s) within 60s of the challenge while none of the controls did. The TGP-S also became bradycardic (the lowest HR over 50 consecutive beats), with the HR decreasing from 260 to 220 vs the controls, whose HR remained constant (approximately 250). We conclude that some rabbits neonatally sensitized to TGP develop apnea and bradycardia upon further intravenous TGP challenge. These studies suggest that cigarette smoke exposure may be associated with a higher rate of SIDS via an anaphylactic mechanism.

Express detection of nonylphenol in water samples by fluorescence polarization immunoassay

The development of express method for detection of endocrine-disrupting chemicals (EDC) such as alkylphenols is required for ecological monitoring. Several attempts have been made to produce antibodies against 4-nonylphenol (NP) in recent years. This work describes the production of new antibodies against NP and also summarizes the characterization of antibodies obtained earlier. Three approaches used to produce alkylphenol-specific antibodies are compared; these are based on: 1. omega-(4-hydroxyphenyl)nonanoic or omega-(4-hydroxyphenyl)heptanoic acid NP derivatives designed to mimic the linear NP isomer; 2. 4-aminophenol, which potentially mimics various substituted phenolic compounds with different side-chain structures at position 4 of the benzene ring; and 3. a mixture of branched NP isomers, conjugated to the carrier protein via a benzene ring by the Mannich reaction, and expected to be the closest mimic of NP structure by preserving its natural alkyl moiety.Fluorescence polarization immunoassays based on different combinations of antibody and labeled antigen for screening detection of NP were developed and structural aspects of assay sensitivity and specificity were investigated. The assays based on the antisera raised against omega-(4-hydroxyphenyl)nonanoic acid and NP conjugate via Mannich reaction are capable of express detection of NP with detection limit of 7 microg mL(-1 )and assay dynamic range of 18-300 microg mL(-1).

[Preclinical study of maxar safety]

The results of preclinical safety evaluation of the new hepatoprotector maxar showed that this drug can be classified as a low-toxicity substance with respect to acute toxicity. No significant functional and structural changes in the systems and organs of experimental animals were observed after a 6-month administration in rats (in a dose of 300, 600, and 1200 mg/kg) and in dogs (500 mg/kg). Maxar exhibited no mutagen and allergen properties, produced no immunotoxicant action, and did not adversely affect the reproduction function.

Molecular and immunochemical characteristics of monoclonal and recombinant antibodies specific to bisphenol A

Four anti-bisphenol A monoclonal antibodies (mabs) were obtained and each characterized by an enzyme-linked immunosorbent assay (ELISA). Among these mabs, BBA-2187 was the most reactive towards bisphenol A. The quantitation limit of the ELISA assay for bisphenol A was 0.13 ng/ml, which is more sensitive than the other immunoassays reported. Then, the cDNA clones encoding variable heavy and variable light chains of these four mabs were isolated, and used for construction of four single-chain Fv (scFv) antibody genes, which were expressed in Escherichia coli cells. The reactivity of four scFv antibodies towards bisphenol A in ELISA was comparable to those of the parent mabs. The most sensitive assay was achieved with BBA-2187scFv. Its cross-reactivity to the related compounds was similar to that of the parent mab. Based on the reactivity of heterologous combinations of VH and VL fragments, it was found that the unique structure of the framework region 2 in the VL of BBA-2187 appeared to be important for specific assembly together with the VH.

Effects of bisphenol A on antigen-specific antibody production, proliferative responses of lymphoid cells, and TH1 and TH2 immune responses in mice

1. We investigated the effect of bisphenol A (BPA), which binds estrogen receptors, on immune responses including production of antigen-specific antibodies, proliferative responses of lymphoid cells, and Th1 and Th2 responses. 2. For this investigation, mice were p.o. given varying doses including 3, 30, 300, and 3000 micro g kg(-1) of BPA immediately after immunization with hen egg lysozyme (HEL) (day 0) and then daily by day 20. On day 21, anti-HEL IgG antibodies in sera and proliferative responses of spleen cells to the antigen were measured. Anti-HEL IgG2a antibodies and IFN-gamma secreted from splenic lymphocytes were also measured as indicators of Th1 immune responses, while anti-HEL IgG1 antibodies and IL-4, as those of Th2 responses. 3. The results showed that treatment with 3000 micro g kg(-1) of BPA was followed by a significant increase in anti-HEL IgG as well as the antigen-specific cell proliferation. Anti-HEL IgG2a production and IFN-gamma secretion were significantly enhanced in mice treated with 300 and 30 micro g kg(-1) of BPA, respectively, while anti-HEL IgG1 production and IL-4 secretion were augmented in animals given 3000 and 300 micro g kg(-1) of the chemical, respectively. 4. Augmentation of these immune responses was also observed in mice exposed to 0.3-30 micro g kg(-1) of estradiol, although Th1 responses appeared to be more sensitive to the sex hormone than Th2 responses. 5. These results suggest that BPA may play a role in augmenting immune responses, especially Th1 responses.

Development of an enzyme-linked immunosorbent assay for bisphenol a using chicken immunoglobulins

Bisphenol A was coupled, after derivatization into a suitable hapten, to bovine serum albumin and ovalbumin in order to produce immunizing and coating antigens. The immunizing antigens were injected into chickens, which allowed the isolation of specific bisphenol A immunoglobulins from the egg yolk. These antibodies were used in an indirect competitive enzyme-linked immunosorbent assay for the determination of bisphenol A in aqueous solutions. Various parameters, influencing the assay sensitivity, were evaluated. The applicability of the assay for the determination of bisphenol A in milk was also studied. The assay was not as sensitive as other analytical techniques used in bisphenol A analysis, since typical I(50) levels of 2.5 microM were reached in aqueous solutions. This study nevertheless illustrates the usefulness and the potency of chicken antibodies in the analysis of migration residues from packaging materials using immunochemical techniques. In addition, the assay showed to be quite specific for bisphenol A as well. Only for bisphenol A analogues, cross reactivities of about 40% were reached, enabling the use of the antibodies for the screening of bisphenol A and alike compounds.

Immunomodulation with DiNAC-- a new approach to the treatment of atherosclerosis?

Not all antioxidants reduce atherosclerosis. This may be because atherosclerosis has an autoimmune, inflammatory pathogenesis. As probucol is both an antioxidant and an immunomodulatory drug, it may be the immunomodulatory effect that underlies its ability to reduce atherosclerosis. N,N-Diacetyl-L-cystine is not an antioxidant but is immunomodulatory. In the Watanabe-heritable hyperlipidaemic rabbit model of familial hypercholesterolaemia, N,N-diacetyl-L-cystine treatment does not lower lipid levels but it does reduce atherosclerosis. Immunomodulation may be a new approach to the treatment of atherosclerosis.

Conjugation, immunoreactivity, and immunogenicity of calix[4]arenes; model study to potential calix[4]arene-based Ac3+ chelators

For the development of calix[4]arene-based radiotherapeutic agents, the conjugation to biomolecules and immunogenicity in mice of potential 225Ac3+-chelating calix[4]arenes were studied. A calix[4]arene triethyl ester isothiocyanate and a bis(calix[4]arene) hexacarboxylic acid, containing a masked thiol functionality, were used in conjugation experiments to a mouse monoclonal antibody and serum albumins. All characterization techniques indicate that only the calix[4]arene carboxylic acid is successfully conjugated to the biomolecules. The immunoreactivity of the conjugates is not impaired when up to 6 equiv of calixarene are bound to the monoclonal antibody. Animal tests indicated that the immunogenicity toward the calix[4]arene is strongly influenced by the nature of the carrier, the dosage, and the injection method. No immune response occurred when a homologous carrier was used or when a heterologous carrier was applied at a dosage of 10 microg per immunization via intravenous injection. Under all other conditions, the presence of antibodies directed against the calix[4]arene was demonstrated. Thus, for the application in radioimmunotherapy, the conjugation of a calix[4]arene to a humanized antibody will probably not lead to an immune response, and the immunoreactivity will not be disturbed.

Formaldehyde and phenol exposure during an anatomy dissection course: a possible source of IgE-mediated sensitization?

The sensitizing potency of formaldehyde and phenol exposure during 4 weeks of an anatomy dissection course was assessed in 45 medical students. Specific IgE against formaldehyde by RAST and by ELISA and specific IgE against phenol by ELISA were assessed before and after the course. At the start of the course, symptoms, type I allergy, respiratory diseases, and smoking habits were noted. At the end of the course, only symptoms experienced during the dissection lessons were assessed. Indoor formaldehyde levels were measured continuously. The mean indoor formaldehyde level was 0.124 +/- 0.05 ppm, with a minimum of 0.059 ppm and a maximum of 0.219 ppm. Specific IgE against formaldehyde or phenol was found in none of the subjects at the beginning of the course, and no student showed specific IgE against formaldehyde or phenol after the course. Assessment of primarily irritant symptoms during the lesson revealed itch and paraesthesia of hands in 33/45 students (P < 0.00005), headache in 15/45 students, burning eyes in 13/45 students (P < 0.02), dizziness in 8/45 students (P < 0.008), sneezing in 4/45 students, epistaxis in 2/45 students, and shortness of breath in 1/45 students. According to our data, 1-month exposure to formaldehyde and phenol during an anatomy dissection course does not induce specific IgE against formaldehyde or phenol.

Activation of the classical pathway of complement by tobacco glycoprotein (TGP)

Tobacco glycoprotein (TGP), a polyphenol-rich glycoprotein isolated from tobacco leaves, activates the classical complement pathway through a mechanism that appears to involve direct interaction with C1q. A binding site on C1q for TGP can be localized by competitive inhibition with DNA to a region located in the junction between the collagen-like and globular regions of the molecule. A protein with activity similar to TGP has also been isolated from cigarette smoke condensate (TGP-S); it shares a binding site on C1q with TGP and has similar functional activity, with the exception that complement activation does not proceed to formation of a C3 cleaving enzyme. The ability of TGP and TGP-S to activate complement can be partially duplicated using polyphenols associated with tobacco leaf and smoke, i.e., chlorogenic acid and rutin. These polyphenols also compete with TGP for a binding site on immobilized C1q, suggesting that the polyphenol portion of TGP is critical for activation of complement. These results provide an additional mechanism for complement activation by cigarette products that, in vivo, could result in a localized complement depletion, generation of biologically active complement cleavage products, and initiation of an inflammatory response.

Characterization of the tobacco glycoprotein surface binding property of heart and skeletal muscle cells. I. Modulation of the heart cell membrane TGP interaction by anti-TGP IgG

Monolayers of L6 rat skeletal myoblast cells formed surface binding isotherms with the purified tobacco leaf glycoprotein TGP1 and the enriched cigarette tar glycoprotein TGP2. Scatchard analysis showed that the binding in the range of the limited concentrations tested was to a single class molecule and the calculated affinity constant (Kd) for TGP1 and TGP2 showed similar values (9.78 x 10(-13) M and 3.09 x 10(-13) M, respectively). The bound TGPs were almost totally displaced by excess nonradiolabeled molecules. The calculated Bmax of the L6 myoblast monolayer was 2.93 fmol for TGP1 and 0.217 fmol for TGP2 per 32.2 mm2. Guinea pig heart sarcolemma binding isotherms were also formed with radiolabeled TGP1 and TGP2. The interaction of tobacco leaf TGP1 with the heart cell membranes was irreversible because only 15-20% of the bound TGP1 was displaced by 100-fold, non-labeled molecules but the interaction of tar TGP2 with heart sarcolemma was reversible and probably saturable. The heart sarcolemma TGP2 affinity constant (Kd) was 5.88 x 10(-7) M and the Bmax, 2.45 x 10(-8) M per 12.5 micrograms sarcolemma. Pretreatment of heart sarcolemma with increasing concentrations of leaf TGP1 did not displace tar TGP2 binding but its absorption on the membrane resulted in increased TGP2 sarcolemma attachment by a complex and unexplained mechanism. Increasing concentrations of the sera of 10 of 15 guinea pigs (67%) that received mainstream emissions of tobacco smoke from a University of Kentucky cigarette smoking machine for 152 days, displaced cigarette tar TGP2 heart cell sarcolemma attachment and this inhibition was significantly different from that produced by the sera of sham smoked and of non-exposed animals (Mann-Whitney test, p = 0.0082). Staphylococcus protein A inhibited the displacement of TGP2 produced by the sera of cigarette smoke exposed guinea pigs and this observation indicated that this action was mediated by IgG molecules. The specific immunoprecipitation of a radiolabeled surface epitope of the L6 myoblast monolayers pretreated with TGP1 or TGP2 by immune IgG against TGP2 and by the IgG of an antiserum against standard TGP showed that the tobacco glycoproteins attached to a unit polypeptide of the plasma membrane of the muscle cells of approximately 76 kDa. These data support the notion that TGP molecules in cigarette smoke are absorbed systemically on smoking and may have a direct toxic effect when they attach to the surface TGP binding proteins of heart and skeletal muscle cells.

Polyerga, a biological response modifier enhancing T-lymphocyte-dependent responses

Cancer patients are often treated with biological response modifiers to enhance immunological functions. However, little is known about the actual mechanism of action of many of these substances. Therefore, we were interested in the effect of i.p. treatment with porcine low-molecular-weight spleen peptides, which are used during supportive cancer therapy, on lymphoid cell populations and function in mice. After treatment with 0.5 microgram peptides/kg body weight for 14 consecutive days, lymphokine secretion and the generation of cytotoxic T-cells were significantly enhanced as compared with controls. However, there was no effect on the number of cells or the percentage of cells expressing functional surface markers in secondary lymphoid organs.

[Sensitizing capacity, cross-reactivity and antigenic determinants of bisphenol A]

Bis-GMA and epoxy resins are known to cause allergic reactions in some patients. The purpose of this research was to investigate the sensitizing capacity, cross-reactivity and antigenic determinants of bisphenol A (BPA), a major constituent of Bis-GMA and BPA type epoxy resins. Anti-BPA antibodies were prepared from mice injected with BPA-ovalbumin conjugates (BPA-OVA), and the reactions of the structurally BPA-related compounds were compared with that of BPA using these antibodies by the enzyme immunoassay (EIA) and EIA inhibition test. The findings are as follows: 1) Injection of BPA failed to generate anti-BPA antibodies. However, injection of BPA-OVA was effective in producing antibodies strongly reacting with BPA. 2) Polyclonal anti-BPA antibodies cross-reacted with bisphenol B (BPB), p-isopropyl-phenol (IPP), diethylstilbestrol (DES) and 2,4-dinitrophenyl (DNP). 3) Five kinds of monoclonal anti-BPA antibodies were obtained. These monoclonal antibodies reacted specifically with BPA and moderately cross-reacted with IPP, DES and BPB, but not with DNP. The results suggest that BPA-OVA is capable of eliciting anti-BPA antibody production in mice and that the antigenic determinant of BPA is the structure of one central carbon atom, covalently bound with two phenyl groups and two methyl groups.

Highly specific polyclonal antisera against estriol: cross-reactivity restriction following affinity chromatography

An immunosorbent technique was developed to attenuate cross-reactivity of a polyclonal antiserum against a 4(2) (rho-carboxyphenylazo)-1,3,5[10]-estratrien-3,16 alpha,17 beta-triol-bovine serum albumin conjugate. The chromatographic separation of antiserum through stationary phases having either rho(carboxymethyl)phenylazo-phenol or rho(carboxymethyl)-phenylazo-2-naphthol side residues reduced the antiserum avidity, while increasing the apparent antiserum affinity and decreasing the residual cross-reactivities against heterologous ligands. The highly specific antiserum obtained allowed the development of a competitive binding assay over an extended analytical range, which opens up the possibility of direct measurement of estriol from the early pregnancy to delivery. The significance of the attenuation of antiserum cross-reactions after affinity chromatography is discussed with reference to epitope-paratope interaction in the case of small endogenous molecules like estrogens.

Relationship between structure and activity of an anti-complementary arabinogalactan from the roots of Angelica acutiloba Kitagawa

An anti-complementary arabinogalactan (AGIIb-1), isolated from the roots of Angelica acutiloba Kitagawa, comprised one neutral (N-I) and two acidic arabinogalactan (A-I and A-II) units and one neutral arabinan unit (N-II). N-I showed the most potent anti-complementary activity. AGIIb-1, A-I, and A-II had similar moderate activities, but N-II had weak activity. The product (AF-AGIIb-1) of digestion of AGIIb-1 with exo-alpha-L-arabinofuranosidase had markedly increased anti-complementary activity, as did that (AF-N-I) of N-I. Degradation of the rhamnogalacturonan core in AGIIb-1 slightly decreased the anti-complementary activity, whereas the high-molecular-weight neutral arabinogalactan and galacto-oligosaccharide side-chains in A-I and A-II showed potent activities. When AF-AGIIb-1 was digested with endo-arabinanase, the activity decreased slightly. Partial elimination of the (1--6)-beta-D-galactosyl side-chains from AF-N-I by digestion with exo-beta-D-galactosidase did not affect the activity. AGIIb-1 reacted weakly with the beta-D-glucosyl-Yariv antigen, but AF-AGIIb-1 and AF-N-1 had increased reactivity with the antigen. The anti-complementary activity of AGIIb-1 was expressed mainly through the classical pathway, whereas AF-AGIIb-1 and AF-N-I had markedly increased activity through the alterative pathway.

Contact allergy to 4,4'-dihydroxy-(hydroxymethyl)-diphenyl methanes: sensitizers in a phenol-formaldehyde resin

A particular phenol-formaldehyde resin of the resol type (P-F-R-2) was shown in a previous study to be a good tracer of patients with contact allergy to phenol-formaldehyde resins. Eleven patients with sensitivity to P-F-R-2 participated in the study in which chromatographically separated fractions of P-F-R-2 were patch tested. This procedure was repeated until a positive reaction to a single substance was noted. In this study 3 new sensitizers are reported. Investigations by mass spectrometry and nuclear magnetic resonance spectrometry identified the compounds to be 4,4'-dihydroxy-3-(hydroxymethyl)-diphenyl methane (4,4'-H-3-HPM), 4,4'-dihydroxy-3,3'-di-(hydroxymethyl)-diphenyl methane (4,4'-H-3,3'-HPM), and 4,4'-dihydroxy-3,5-di-(hydroxymethyl)-diphenyl methane (4,4'-H-3,5-HPM). Six of the 11 patients reacted to at least one of these compounds. All 6 patients reacted to 4,4'-H-3,3'-HPM and 5 reacted simultaneously to 4,4'-H-3-HPM. Four patients reacted to all 3 compounds tested. By patch testing with serial dilutions (ethanol 99.5%) of the three 4,4'-H-HPM, positive reactions were noted down to 0.5 X 10(-6)%, 1.0 X 10(-6)%, and 1.3 X 10(-3)% w/v for 4,4'-H-3-HPM, 4,4'-H-3,3'-HPM, and 4,4'-H-3,5-HPM, respectively.

IgM antibodies against phenolic glycolipid I from Mycobacterium leprae in leprosy sera: relationship to bacterial index and erythema nodosum leprosum

Serum IgM antibodies against Mycobacterium leprae-derived phenolic glycolipid I (PG) were determined in 121 leprosy patients, in contacts and controls by an enzyme-linked immunosorbent assay technique. Anti-PG IgM levels correlated with disease classification, increasing from the tuberculoid towards the lepromatous pole of the disease spectrum. There was a linear correlation between serum IgM PG-antibody levels and bacillary index (BI), a measure of bacterial load. Elevated anti-PG IgM in bacillary negative patients was usually indicative of active disease, undetected by BI. We conclude that anti-PG IgM levels are valuable for monitoring the degree of disease activity. Serum anti-PG IgM levels were significantly lower in patients with erythema nodosum leprosum (ENL) as compared to those without ENL, suggesting that IgM PG-antibodies are also involved in the pathogenesis of ENL.

Analysis of the major antigenic determinants of the characteristic phenolic glycolipid from Mycobacterium leprae

Antibodies to the major phenolic glycolipid purified from Mycobacterium leprae have been demonstrated previously in sera of leprosy but not tuberculosis patients using an ELISA. The major antigenic determinants on this molecule were investigated using antisera raised in rabbits to the purified glycolipid and with a pool of sera from human lepromatous leprosy patients. A small, but significant cross-reaction was observed with the glycolipids from M. bovis and M. kansasii, which contain the phenolphthiocerol dimycocerosate part of the molecule but have different sugars, and also with a semi-synthetic 'attenuation indicator lipid' which shares the phenolphthiocerol but has no sugars. There was however no cross-reaction with phthiocerol dimycocerosate. The disaccharide, corresponding to the two terminal sugars of the M. leprae glycolipid has been chemically synthesized and shown to inhibit the reaction between glycolipid and antibody in the ELISA. The cross-reactivity observed with the M. bovis and M. kansasii glycolipids was not inhibited by the synthetic disaccharide. These findings suggest that the cross-reactivity is associated with the phenol ring and implies the disaccharide may be a unique antigenic determinant of M. leprae.

Serologic studies on porcine strains of Haemophilus parahaemolyticus (pleuropneumoniae): extraction of type-specific antigens

By the use of phenol water extraction it was possible to obtain strictly serotype-specific antigens from mucoid cell cultures of five serotypes of Haemophilus parahaemolyticus (pleuropneumoniae). These serotype-specific antigens did not cross-react with each other in immunodiffusion tests. The type-specific precipitating phenol-water-fractions were composed of two to four antigenic components, presumably of polysaccharide or lipopolysaccharide nature.

Structural studies on induced antibodies with defined idiotypic specificities. I. The heavy chains of anti-p-azophenylarsonate antibodies from A/J mice bearing a cross-reactive idiotype

Amino acid sequence analysis has been performed on three groups of heavy (H) chains of A/J mice. H chains derived from unimmunized animals were compared to anti-p-azophenylarsonate (anti-Ar) antibodies which were further subdivided into those possessing and those depleted of a cross-reacting idiotype (CRI). It was found that anti-Ar antibodies bearing the CRI are homogeneous through the first hypervariable region of the H chain. The same sequence was obtained for pooled antibody isolated from the ascites fluid of 18 A/J mice or from a single mouse. The H chains appear to belong to a minor V-H subgroup. In the first 30 positions Anti-Ar antibodies depleted of the CRI had the same sequence as those containing the CRI (with small amounts of heterogeneity at some positions), but contained a mixture of sequences in the first hypervariable region of the H chain. These studies indicate that antibodies with similar specificity and with identical framework sequences, but which differ in their hypervariable regions, contain different idiotypic determinants, and support the concept that the idiotypic determinants reside primarily within hypervariable regions.