Skin testing of gallic acid-based hair dye in paraphenylenediamine/paratoluenediamine-reactive patients.

Incidence of allergic contact dermatitis (ACD) to para-phenylenediamine (PPD)/paratoluenediamine (PTD) hair dyes is increasing. Hair dyes utilizing gallic acid (GA) may be a safe alternative. However, pretesting is recommended. We investigated the contact sensitivity to ingredients of a dye product; GA, monoethanolamine thioglycolate (MT), l-cystein and ferrous sulfate, and an appropriate pretest method in 31 patients reactive to PPD and/or PTD. An open test was performed with the test dye following the patch test. Subsequently, a use test was performed twice, with a 4-week interval. One subject showed a positive reaction to ferrous sulfate in the patch test. Another subject reacted to the first compound alone in the open test. Thirteen subjects manifesting cutaneous lesions from previous regular hair dyeing, showed reactions at the first use of the test dye; and six had reactions with reduced severity at the second test. GA and MT are safe for use in ACD patients reactive to PPD and/or PTD. For predicting contact allergy to hair dyes, the open test appeared to be a better pretest method than the patch test.

Peanut protein sensitivity towards trace iron: a novel mode to ebb allergic response.

Peanut is a rich source of plant protein which is inexpensive and abundant in nature. The peanut proteins however cause hypersensitive immunogenic responses in certain individuals. A minute amount of contamination may cause strong allergic reactions and even death. Many chemical pretreatment procedures have been developed and prescribed earlier for removal of this allergenicity. In the present article we have observed trace level Fe(III) and Cu(II) complexation of the protein fractions of peanut at pH 4.8 using different spectral methods. Consequently we studied the allergic response of Fe(III) complex of the protein fractions using competitive enzyme linked immunosorbent assay (ELISA) technique and found that there were considerable losses in allergenicity of conarachin I and arachin fractions upon complexation. Immunoassay of Cu(II) complex was avoided keeping in view the Cu toxicity in living systems. The results bring up a new strategy towards reduction of allergenicity using an inexpensive and simple methodology.

Effects of germanium biotite supplement on immune responses of vaccinated mini-pigs to foot-and-mouth disease virus challenge.

Since the outbreaks of foot-and-mouth disease (FMD) in South Korea in 2010-2011, a trivalent vaccine has been used as a routine vaccination. Despite the high efficacy of the trivalent vaccine, low antibody formation was reported in the pig industry and there is considerable concern about the ability of the vaccine to protect against the Andong strain responsible for recent outbreaks in South Korea. To overcome these problems, immunostimulators have been widely used to improve vaccine efficacy in South Korea, although without any scientific evidence. Based on the current situation, the aim of this study was to investigate the effects of germanium biotite, a feed supplement used to enhance the immune system, on the immune responses to FMD vaccination through the Andong strain challenge experiment in trivalent vaccinated pigs. Following the challenge, the germanium biotite-fed pigs showed high levels of IL-8 in serum, and increased cellular immune responses to stimulation with the Andong strain antigen compared to nonsupplemented pigs. In addition, higher FMD virus (FMDV) neutralizing antibody titers were detected in the germanium biotite-fed group than in the nonsupplemented group before the challenge. The findings of this study indicate that germanium biotite supplement might enhance immune responses to the FMD vaccine in pigs.

The soluble nickel component of residual oil fly ash alters pulmonary host defense in rats.

The soluble metal fraction of residual oil fly ash (ROFA) has been shown to increase the susceptibility to infection in animal models. The goal of this study was to determine which of the primary soluble metals or metal combinations in ROFA were responsible for the increased infectivity. The soluble fraction of ROFA contained Ni, Fe, Al, and Zn. On Day 0, Sprague-Dawley rats were intratracheally (IT) instilled with NiCl2 (55.7 microg/rat), FeSO4 (32.7 microg/rat), Al3(SO4)2 (46.6 microg/rat), or ZnCl2 (8.69 microg/rat), or a combination of all the metals (Total Mixture). In a separate experiment, rats were instilled with metal mixtures, including the total mixture, and mixtures without Fe (Mix--No Fe), Ni (Mix--No Ni), Al (Mix--No Al), or Zn (Mix--No Zn). At Day 3, rats were instilled with 5 x 10(4) Listeria monocytogenes. At Days 6, 8 and 10, left lungs were removed to assess bacterial clearance. Bronchoalveolar lavage (BAL) was performed on right lungs on Day 3, before infection, and on Days 6, 8 and 10 to assess lung injury and cellular activity. Prior to infection, soluble Ni and mixtures containing Ni significantly increased lung injury, inflammation, and oxidative damage to a comparable degree when compared to control. Post-infection, rats pre-treated with soluble Ni, alone or in a metal mixture, had increased bacterial lung burden on Day 6, and body weight decreased in the soluble Ni, Mix--No Fe, and Mix--No Al groups post-infection, indicating Fe and Al may act antagonistically to Ni. Ni alone and in metal mixtures increased reactive oxidants in the lung and appeared to be the most important factor in suppressing T-cell activity post-infection. Soluble Ni is likely the primary metal involved in the increased susceptibility to infection observed in rats exposed to the soluble metals of ROFA.

Experimental determination of the absolute enantioselectivity of an antibody-catalyzed Diels-Alder reaction and theoretical explorations of the origins of stereoselectivity.

The exo and endo Diels-Alder adducts of p-methoxycarbonylbenzyl trans-1,3-butadiene-1-carbamate and N,N-dimethylacrylamide have been synthesized, and the absolute configurations of resolved enantiomers have been determined. On the basis of this information, the absolute enantioselectivities of the Diels-Alder reaction catalyzed by antibodies 13G5 and 4D5 as well as other catalytic antibodies elicited in the same immunizations have been established. The effects of different arrangements of catalytic residues on the structure and energetics of the possible Diels-Alder transition states were modeled quantum mechanically at the B3LYP/6-311++G**//B3LYP/6-31+G** level of theory. Flexible docking of these enantiomeric transition states in the antibody active site followed by molecular dynamics on the resulting complexes provided a prediction of the transition-state binding modes and an explanation of the origin of the observed enantioselectivity of antibody 13G5.

An antibody exo Diels-Alderase inhibitor complex at 1.95 angstrom resolution.

A highly specific Diels-Alder protein catalyst was made by manipulating the antibody repertoire of the immune system. The catalytic antibody 13G5 catalyzes a disfavored exo Diels-Alder transformation in a reaction for which there is no natural enzyme counterpart and that yields a single regioisomer in high enantiomeric excess. The crystal structure of the antibody Fab in complex with a ferrocenyl inhibitor containing the essential haptenic core that elicited 13G5 was determined at 1.95 angstrom resolution. Three key antibody residues appear to be responsible for the observed catalysis and product control. Tyrosine-L36 acts as a Lewis acid activating the dienophile for nucleophilic attack, and asparagine-L91 and aspartic acid-H50 form hydrogen bonds to the carboxylate side chain that substitutes for the carbamate diene substrate. This hydrogen-bonding scheme leads to rate acceleration and also pronounced stereoselectivity. Docking experiments with the four possible ortho transition states of the reaction explain the specific exo effect and suggest that the (3R,4R)-exo stereoisomer is the preferred product.

Follow-up of workers from the prefabricated concrete industry after the addition of ferrous sulphate to Danish cement.

Ferrous sulfate has been added to cement manufactured in Denmark, reducing the water soluble chromate content to not more than 2 ppm, since September 1981. A comparison is made between the medical and employment status of a cohort of workers engaged, or who had been engaged, in the manufacture of prefabricated concrete building components in 1981 and in 1987. Workers who had allergic cement eczema in 1981 appeared to show no improvement 6 years after the reduction of chromate in the cement. Improvement was seen, however, in the eczema of those workers with irritant cement eczema. The 1987 study showed that a larger number of chromate-sensitized workers required medical services and topical steroid treatment than did those who were not sensitized to chromate. This difference was statistically significant. The worse medical prognosis of the chromate-sensitized workers could in part be due to the fact that some of these had secondary contact sensitivity to cobalt and rubber chemicals. The chromate-sensitized workers also took earlier retirement. Younger workers with allergic and irritant cement eczema continued to work and their employment status was not influenced by chromate sensitization.

Human milk-derived lactoferrin inhibits mitogen and alloantigen induced human lymphocyte proliferation.

Purified lactoferrin (LF), isolated from human milk, was tested for its effect on human T-lymphocyte proliferative responses to phytohemagglutinin (PHA) and to alloantigens in mixed lymphocyte culture. LF inhibited proliferation in both assays in a dose-dependent manner. The suppressive effect was not due to LF mediated cytotoxicity since washing cells that had been pre-incubated with LF restored their proliferative activity. LF was most effective in suppressing the PHA response when added within 24 h of culture initiation. Iron saturated LF failed to inhibit PHA-induced proliferation, suggesting that the mechanisms of suppression involve the chelating property of LF. The suppressive effect of LF on T-lymphocyte proliferative response in vitro supports the notion that LF has significant immunoregulatory potential in vivo.