Enalaprilat versus cilazaprilat: a comparison of allergic skin reactions in the guinea pig.

ACE-inhibitors have for some time been used in the treatment of hypertension. Apart from inhibiting the conversion of angiotensin I to II, the drugs also affect the metabolism of some inflammatory agents, like bradykinin and substance P. Egg albumin (EA)-sensitized guinea pigs were pretreated with the ACE-inhibitors. Measurement of flare and wheal areas induced by an intradermal injection of EA, showed that enalaprilat significantly increased, whereas cilazaprilat slightly decreased, the reaction area. Enalaprilat also showed an enhancement in histamine and substance P (SP) contents in the skin. In vitro incubation of guinea pig biopsies with enalaprilat potentiated EA- but not SP-induced histamine release. The EA-induced effect was abolished if the animals were pretreated with capsaicin. The conclusion is that cilazaprilat, in contrast to enalaprilat, does not potentiate inflammatory reactions in the guinea pig.     

Acute stress modulates the irritant component of sensitizers in allergic contact dermatitis: implications for exposure assessment

Exposure of skin to noxious environmental stimuli can cause allergic contact dermatitis (ACD), which is a major health risk. Epidemiological studies have determined that 40% of workers report that their jobs are very, or extremely, stressful, and the number of chemicals to which workers are exposed increases each year. We hypothesized that combined exposure to a workplace stressor and a sensitizing chemical would alter the time course and magnitude of the skin immune response. We assessed the mixed exposure of chemical and restraint stress using three potent skin sensitizers, 2,4 dinitrofluorbenzene (DNFB), dicyclohexylcarbodiimide (DCC), and oxazolone, (OXA) on the ear swelling response in stress-susceptible BALB/c mice. Quantitative analyses showed that the dose-response relationship for each chemical followed a cubic trend. Although stress did not alter the shape of the curve, application of restraint stress on day 1 or on day 6 diminished the ear swelling response to 0.1% DNFB. However, if the concentration of the challenge dose was increased to a more irritating concentration, 0.25% DNFB, ear swelling was enhanced. Restraint stress applied on day 6 also increased ear swelling in response to the highly irritating sensitizer DCC, but not to the low-irritancy chemical OXA. These data support the hypothesis that dose-response relationships exist for sensitization with chemical and that restraint stress modulation of the ear swelling response is both chemical specific and dependent on the irritancy potential of the chemical.     

基于RBL-2H3细胞和ICR小鼠过敏与类过敏叠加模型评价注射用血塞通(冻干)过敏与类过敏反应

目的 建立过敏和类过敏叠加的RBL-2H3细胞和ICR小鼠动物模型,对注射用血塞通(冻干)(XST)的过敏与类过敏反应进行评价研究。方法 体外以RBL-2H3细胞的β-氨基己糖苷酶(β-Hex)和组胺释放率为评价指标,确定抗二硝基苯单克隆抗体(DNP-IgE)、DNP-牛血清白蛋白(BSA)的剂量及与C48/80(30 μg·mL^-1)作用的最佳时间,筛选过敏和类过敏叠加模型的阳性条件,随后考察XST (4、8、16 mg·mL^-1)对细胞活力及与DNP-IgE/BSA叠加后对细胞脱颗粒的影响。体内以ICR小鼠为实验对象,以(类)过敏反应症状分值及血浆中免疫球蛋白E (IgE)、组胺、5-羟色胺、血管内皮生长因子A (VEGF-A)、末端补体复合物(SC5b-9)含量为评价指标,筛选卵蛋白(OVA,2.5、5.0、10.0 mg·kg^-1)、C48/80(1、2、4 mg·kg^-1)过敏-类过敏模型阳性条件,最后对XST (60、120、240 mg·kg^-1)的致敏性及是否会产生过敏、类过敏反应进行评价。结果 体外细胞实验最终确定400 ng·mL^-1的DNP-IgE致敏后用50 ng·mL^-1的DNP-BSA激发的同时与C48/80共同作用30 min作为过敏与类过敏叠加阳性组;16 mg·mL^-1的XST与DNP-IgE/BSA联合叠加时,与单给DNP-IgE/BSA或XST组比较均促进组胺和β-Hex的释放(P<0.01)。体内小鼠实验中5、10 mg·kg^-1的OVA均会使小鼠体内IgE显著升高,依据过敏样反应分值和小鼠血浆内组胺、VEGF-A和SC5b-9含量最终确定5 mg·kg^-1 OVA与1 mg·kg^-1 C48/80建立叠加模型,耳、肺及支气管组织中可见明显的水肿及炎性细胞浸润。单纯的XST不会对小鼠致敏,但是与OVA介导的过敏反应叠加后,与单给DNP-IgE/BSA或XST组比较,会显著提高血浆中内组胺、VEGF-A和SC5b-9水平(P<0.05、0.01),与建立的过敏-类过敏叠加模型表现出较好地一致性。结论 体外体内实验均表明IgE介导的过敏反应和C48/80引起的类过敏反应会产生叠加作用,加剧过敏介质的释放和免疫反应程度。同时此模型的建立也验证了XST存在过敏与类过敏叠加现象,该模型可为中药注射剂的临床前安全性评价及合理用药提供参考。     

Effect of cianidanol (KB-53) on delayed skin reactions in mice compromised by carbon tetrachloride and 1-naphthylisothiocyanate

A study was carried out to investigate the influence of 3 kinds of hepatotoxic agents on the peripheral blood leucocyte population, the splenocyte population and the delayed type hypersensitivity (DTH) in mice. These parameters were not affected by the intraperitoneal injection of D-galactosamine (Gal). The intensity of picryl chloride induced DTH (PC-DTH) in mice was significantly lowered with the administration of carbon tetrachloride (CCl4) and 1-naphtylisothiocyanate (ANIT) in a dose-dependent manner after the mice were sensitized to picryl chloride (PC) from one to three days after the subcutaneous injection of CCl4 and ANIT. However the peripheral blood leucocyte population and splenocyte population were not affected by these chemicals. The lowering effect of CCl4 and ANIT on PC-DTH was somewhat weakened when PC sensitization was performed seven days after the injection of CCl4 and ANIT. No lowering effect was observed when PC sensitization was performed fourteen days after the injection of CCl4 and ANIT. The intensity of PPD induced DTH (PPD-DTH) was also lowered by the administration of CCl4 and ANIT when the sensitization to tubercle bacilli was performed three days after the injection of CCl4 and ANIT. Cianidanol (KB-53) prevented the decrease of PC-DTH and PPD-DTH in the mice injected with CCl4 and ANIT in a dose-dependent manner, but did not affect DTH in normal mice. So it seems that KB-53 has an immunostimulating effect on decreased cellular immunity.     

Characterization of Ascaris-induced biphasic skin allergic reaction model in mice: possible roles of mast cells in early-phase and CD4-positive T cells in late-phase reactions

We established an Ascaris-induced biphasic skin allergic reaction in mice. In the early-phase reaction (EPR), mast cell degranulation was observed, and tranilast inhibited ear edema. In mast-cell-deficient mice (WBB6F(1)-W/W(V) mice), ear edema in the EPR disappeared, whereas that in the late-phase reaction (LPR) remained. Eosinophils increased, and CD4-positive T cells tended to increase in the LPR. Anti-CD4 antibody, anti-IL-4 antibody and anti-IL-5 antibody all inhibited ear edema and had a tendency to inhibit eosinophil infiltration in the LPR. These data suggest that the EPR is induced by histamine released from mast cells, whereas the LPR is induced by IL-4 and IL-5 produced from CD4-positive T cells.     

Inhibitory effect of epinastine on the type II-IV allergic reactions in mice, rats and guinea pigs.

The inhibitory effect of epinastine (WAL 801 CL, CAS 80012-43-7) on types II, III and IV allergic reactions was studied. Epinastine caused an inhibition of type II allergic reactions: 1. the swelling of rat foot pad induced by a subcutaneous injection of anti-rat rabbit antiserum, and 2. lethality induced by an intravenous injection of anti-SRBC (sheep red blood cells) rabbit serum into guinea pigs (Forssman systemic reaction). The drug also caused an inhibition of the early phase in active Arthus reaction in guinea pigs (type III reactions). However, no significant inhibition was detected in the delayed-hypersensitivity reaction (type IV allergic response) induced by sheep red blood cells or picryl chloride in mice.     

The pathogenesis of synergistic lung damage in mice by an environmental irritant (H2SO4) and particulate antigen

Daily inhalation by mice of an environmental irritant (H2SO4) followed by consequent respiratory immunization with a particulate antigen (sheep red blood cells, SRBC) induced severe interstitial pneumonitis. Inhalation of H2SO4 per se resulted in accumulation of i.v. injected globulin in the lungs of mice, without significant change in lung weight. In addition, when marker colloidal carbon particles were injected i.v. following H2SO4 inhalation, the carbon was rapidly trapped in the capillary wall in the lungs. Homologous anti-SRBC serum instilled into the respiratory tract followed by subsequent SRBC inhalation produced inflammation and injury similar to that generated by H2SO4 in combination with particulate antigen. It is postulated that following irritant inhalation, the permeability of alveolocapillary membranes increases, so that immune complexes formed by pre-existing circulating antibodies and inhaled antigen can initiate subsequent lung injury.     

Utility of MTT assay in three-dimensional cultured human skin model as an alternative for draize skin irritation test: approach using diffusion law of irritant in skin and toxicokinetics-toxicodynamics correlation

Purpose. A cytotoxicity assay using a three-dimensional cultured human skin model, Living Skin Equivalent-high (LSE-high) was evaluated as an alternative to the Draize skin irritation tests using animals. A relation between the cytotoxicity and calculated concentration of an irritant in skin was also evaluated. Methods. Colorimetric thiazoyl blue (MTT) conversion assay and a surfactant, cetylpyridinium chloride (CPC), were selected as a cytotoxicity assay and a model irritant. The fraction of dead cell number in the MTT assay or the Draize irritation score (in vitro and in vivo irritation data, respectively) was treated as a function of CPC concentration in the viable skin of LSE-high and guinea pig. Separately, in vitro permeations of CPC through the LSE-high or excised guinea pig skin were determined to calculate the average concentration of CPC in the viable skin using the Fickian diffusion theory. The obtained relations between the irritation scores and CPC concentration were evaluated by the Emax model (Hill equation). Results. CPC concentration showing 50% irritation (IC ₅₀) was similar for the MTT assay (18.9%) and Draize test (12.3%), and a good relationship (r = 0.981) was observed between the fraction of dead cell number and the Draize score. In contrast, IC ₅₀, 1.32%, for the MTT assay in LSE-high was much lower than that using guinea pig skin. We then corrected the results for the MTT assay using a ratio of IC ₅₀ in guinea pig skin against LSE-high, resulting in a good relation between both MTT results in guinea pig skin and LSE-high. Conclusion. The present results suggest that the MTT assay using LSE-high may be utilized as an alternative for the Draize test in animals for evaluating skin irritation.     

Tedizolid (torezolid) for the treatment of complicated skin and skin structure infections

ABSTRACT

Introduction

Acute bacterial skin and skin structure infections (ABSSSI) are among the most frequent infectious diseases. Recently, several new antibiotics with activity against MRSA have been approved. Tedizolid, a second-generation oxazolidinone approved for ABSSSI offers theoretical advantages over first-generation oxazolidinones.     

Pro-oxidative versus antioxidative reactions between Trolox and Cr(VI): The role of H(2)O(2)

The effect of the Vitamin E model compound Trolox in reactions with Cr(VI) in the presence or absence of hydrogen peroxide was investigated. The aim of this study was to establish and discuss potential Trolox-mediated pro-oxidative reactions. The importance of the Trolox:Cr(VI) ratio in the Cr(VI) reduction process was determined from the EPR spectra and DNA cleavage reactions. In the absence of hydrogen peroxide, reduction of Cr(VI) occurred with concomitant oxidation of Trolox to the phenoxyl radical. In the presence of hydrogen peroxide, Cr(V), produced by the reduction of Cr(VI), reduced hydrogen peroxide to the hydroxyl radical. The latter was detected by spin-trapping the methyl radical following reaction with N-methyl sulfoxide. During Cr(VI) reduction with Trolox, DNA single- or double-strand breaks due to Trolox radical formation were not observed. Relaxed DNA appeared only when H(2)O(2) was added to Trolox/Cr(VI) mixtures most probably due to hydroxyl radical formation during the redox cycling of Cr(V/IV)-species. Fenton-like reactions do not play a significant role in the Trolox/Cr(VI) system in the absence of added H(2)O(2).     

Reactions of N-alkoxycycliminium salts, VIII: reactions of N-methoxypyridinium salts with aromatic amines and sulfonamides. (author's transl)

Reactions of N-Alkoxycycliminium Salts, VIII: Reactions of N-Methoxypyridinium Salts with Aromatic Amines and Sulfonamides. The 1-(methoxyimino)pentadienes 2 - 12 are prepared by reaction of N-methoxypyridinium salts 1 with aromatic amines and sulfonamides in dipolar aprotic solvents. Some reactions require the presence of a base. The u.v., i.r. and n.m.r. spectra of the products are discussed.     

An Integrated Assessment Scheme for assessing the adequacy of (eco)toxicological data under REACH

REACH requires all available (eco)toxicological information, whether protocol studies, other experiments, or non-testing approaches such as read-across or (Q)SAR, to be collected and evaluated. However, guidance documents only limitedly address how adequacy of (eco)toxicological information can be assessed consistently and transparently. We propose an Integrated Assessment Scheme (IAS) for the evaluation of (eco)toxicological data. The IAS consists of three modules: (i) the reliability of the data; (ii) the validity of the methods the data are generated from and; (iii) the regulatory need of the data. Each module is assessed and documented using adjusted OECD principles for the validation of (Q)SARs. These adjusted principles provide a harmonised set of criteria for the evaluation of all types of (eco)toxicological data. Assessment codes, similar to Klimisch codes, are assigned to the evaluated information in each module. The coherent combination of the assessment codes of all three modules determines the overall adequacy of information for fulfilling the information requirement in REACH, and can serve as a weight in a Weight of Evidence procedure as mentioned in REACH Annex XI.     

Inhibitory effects of water-soluble low-molecular-weight beta-(1,3-1,6) d-glucan purified from Aureobasidium pullulans GM-NH-1A1 strain on food allergic reactions in mice

There have been a number of reports showing that the crude beta-glucan fraction prepared from various kinds of Basidiomycetes mushrooms acts as anti-cancer and anti-allergic reagent through stimulation of IFN-gamma production. It has been reported, however, that the exposure of the airway to beta-(1,3) d-glucan, contained in house dust, indoor moulds and some bacteria, potentiates the airway allergic response. It seems likely that the discrepant effects on immune function may be related to such factors as differences of the administration route, average molecular weight and water solubility. We isolated a new low-molecular-weight (about 100 kDa) beta-glucan from Aureobasidium pullulans 1A1 strain of black yeast, and found that it had low viscosity and was water-soluble. In this study, we examined the effects of water-soluble low-molecular-weight beta-(1-->3) and 50-80% branched beta-(1-->6) glucan (LMW-beta-Glucan) isolated from A. pullulans on the ova-albumin (OVA)-treated allergic reaction in mice. Feeding standard laboratory diets containing 0.5 and 1% LMW-beta-Glucan significantly inhibited the OVA-specific IgE elevation compared to that in OVA-sensitized mice fed standard laboratory diet alone (control). Furthermore, feeding standard laboratory diets containing 0.5 and 1% LMW-beta-Glucan inhibited the reduction of IL-12 and IFN-gamma production from splenocytes and the reduction of CD8- and IFN-gamma-positive cell number in the small intestine of the OVA-sensitized mice. These findings suggest that anti-food allergic action of LMW-beta-Glucan may be due to the inducing IFN-gamma production in the small intestine and splenocytes.     

Photosensitized decomposition of contraceptive steroids: a possible explanation for the observed (photo)allergy of the oral contraceptive pill

The photosensitized decomposition of the main steroids used in oral contraceptives was studied. Under the circumstances applied, ethinyl estradiol and norethynodrel decomposed rapidly (t 1/2 = 11.0 + or - 0.2 minutes for ethinyl estradiol and 5.7 + or - 0.4 minutes for norethynodrel). The decomposition product of ethinyl estradiol has been identified as 17 alpha-ethynyl-10 beta-hydroperoxy-17 beta-hydroxyestra-1,4-dien-3-one. The decomposition products of ethinyl estradiol and norethnodrel were previously found in experiments in which the irreversible binding of these steroids to protein was studied. Photosensitized decomposition of the steroids may be the cause of photoallergic side effects of "the pill."     

血液中嗜酸性粒细胞与气道高反应性关系分析

目的探讨支气管哮喘家系气道高反应性(BHR)与其血液中嗜酸性粒细胞(EOS)的关系。方法通过对支气管哮喘(bronchialAsthma)家系4228人气道高反应性者中取血样进行EOS计数,并对结果进行分析。结果BHR( )组血液中EOS数在不同年龄组都明显高于BHR(-)组,差异具有非常显著性(P<0.01)。结论EOS计数应列为支气管哮喘家系的临床诊断特征性指标之一,可为临床提供有力的诊断依据及诊断的准确性。     

Intralaboratory validation of alternative endpoints in the murine local lymph node assay for the identification of contact allergic potential: primary ear skin irritation and ear-draining lymph node hyperplasia induced by topical chemicals

We validated a two-tiered murine local lymph node assay (LLNA) with a panel of standard contact (photo)allergens and (photo)irritants with the aim of improving the discrimination between contact (photo) allergenic potential and true skin (photo)irritation potential. We determined ear weights to correlate chemical-induced skin irritation with the ear-draining lymph node (LN) activation potential. During tier I LLNAs, a wide range of concentrations were applied on three consecutive days to the dorsum of both ears. Mice were exposed to UVA light immediately after topical application to determine the photoreactive potential of some test chemicals. Mice were killed 24 h after the last application to determine ear and LN weights and LN cell counts. It was possible to classify the tested chemicals into three groups according to their threshold concentrations for LN activation and skin irritation: (1) chemicals with a low LN activation potential and no or very low skin irritation potential; (2) chemicals with a marked LN activation potential higher than a distinct skin irritation potential; and (3) chemicals with LN activation potential equal to or lower than their skin irritation potential. Group 1 consisted only of contact allergens, indicating that LN activation in the absence of skin irritation points to a contact allergenic activity. Since groups 2 and 3 comprised irritants and contact allergens, a tier II LLNA protocol was used to finally differentiate between true irritants and contact allergens. Briefly, mice were pretreated with mildly to moderately irritating concentrations of the chemical to the shaved back and after 12 days were challenged on the ears as described above in order to elicit a contact allergenic response in the ear skin and the ear-draining LN. With this approach, tier II LLNAs have to be conducted only in cases for which skin irritation potential is in the range of LN activation potential and no structure-activity relationship data indicating a contact allergenic hazard are available.     

A method for measuring mouse respiratory allergic reaction to low-dose chemical exposure to allergens: An environmental chemical of uncertain allergenicity,a typical contact allergen and a non-sensitizing irritant

Our aim was to improve a method for detecting respiratory hypersensitivity by testing three confirmed respiratory allergens (trimellitic anhydride [TMA], phthalic anhydride [PA] and toluene diisocyanate [TDI]), an environmental chemical of uncertain allergenicity (2,4-d-butyl [DB]), a confirmed contact allergen (2,4-dinitrochlorobenzene [DNCB]) and a standard irritant (sodium dodecyl sulfate [SDS]). BALB/c mice were topically sensitized (nine times in 3 weeks) with these chemicals, then challenged via the trachea. One day post-challenge, samples were taken from the mice to assay for total immunoglobulin (IgE and IgG₁) levels in serum and bronchoalveolar lavage fluid (BALF); differential cell counts and cytokine/chemokine levels in BALF; lymphocyte counts and surface antigen expression on B-cells within lung-associated lymph nodes (LNs); ex situ cytokine production by cells from these LNs; and gene expression in BALF (CCR3) and LNs (CCR4, STAT6 and GATA-3). The three confirmed respiratory allergens and DB induced immune response characteristic of immediate-type respiratory reactions, as evidenced by increased total IgE and IgG₁ levels; influx of eosinophils, neutrophils, chemokines and cytokines in BALF; increased surface antigen expression on B-cells in LNs; increased Th2 cytokine production in LNs; and increased respiratory allergy-related gene expression in both BALF and LNs. In contrast, DNCB and SDS treatments yielded, at most, insignificant increases in all respiratory allergic parameters. Thus, the protocol was equally suitable for use with an environmental chemical of unknown allergenicity and for typical respiratory allergens. Since the protocol differentiated respiratory allergens from contact allergens and irritants, it may be useful for detecting respiratory allergy related to environmental chemicals.     

Morphine-induced analgesia in the hot-plate test: comparison between NMRI(nu/nu) and NMRI mice

NMRInu/nu mice are frequently used in cancer research, but their use in behavioural pain tests is unexplored. As behaviour of NMRI mice in pain tests is well-documented, a hot-plate test was performed comparing acute thermal nociception in NMRInu/nu and NMRI mice - untreated and morphine-treated - to estimate the usefulness of NMRInu/nu mice for further research on cancer pain. In both strains, morphine dose-dependently increased response latencies, number of animals reaching cut-off times and AUC values. Yet in NMRInu/nu mice, as compared to NMRI mice, all curves were shifted to the right. In order to be comparable, cut-off times must express a similar degree of baseline response augmentations. NMRInu/nu mice had substantially lower pre-drug latencies, indicating a lowered threshold for painful thermal stimuli, therefore effects of morphine in NMRInu/nu mice were also analysed using a lower cut-off time. Doing so, morphine resulted in similar effects in both strains. The effects were independent of hot-plate temperature, because similar results were obtained using temperatures of 50 and 55 degrees. The different morphine sensitivity of NMRInu/nu compared to NMRI mice primarily seems to depend upon differences in thermal threshold, probably induced by the different genotype of both strains. To determine whether cancer alters pain threshold or morphine analgesia, LoVo tumour-bearing NMRInu/nu mice were also tested. The tumour presence had no influence on withdrawal latencies or morphine efficacy. In general it can be concluded that NMRInu/nu mice with or without tumour can be used for nociceptive testing if baseline sensitivity is properly defined.     

Levocetirizine: a review of its use in the management of allergic rhinitis and skin allergies

Levocetirizine (Xyzal) is a selective, potent, oral histamine H(1) receptor antagonist of the latest generation that is licensed for the symptomatic treatment of allergic rhinitis (including persistent allergic rhinitis [PER]) and chronic idiopathic urticaria (CIU). Large, well designed trials indicate that levocetirizine is effective and generally well tolerated in the treatment of allergic rhinitis and CIU. Its pharmacological profile offers many positive aspects: a rapid onset and long duration of antihistaminic effect; rapid absorption and high bioavailability; a low potential for drug interactions; a low volume of distribution; and a lack of effect on cognition, psychomotor function and the cardiovascular system. Allergen challenge chamber studies suggest that levocetirizine has better efficacy than desloratadine, loratadine or fexofenadine. Well controlled, long-term studies with other later-generation H(1) receptor antagonists are required to fully define its clinical profile relative to other agents in this class. Overall, levocetirizine is a valuable addition to the oral H(1) receptor antagonists available for the treatment of allergic rhinitis and as first-line therapy in patients with CIU.