Preservation of resin–dentin interfaces treated with benzalkonium chloride adhesive blends

Reducing collagen degradation within hybrid layers may contribute to the preservation of adhesive interfaces. This study evaluated the stability of resin–dentin interfaces treated with benzalkonium chloride (BAC)‐modified adhesive blends and assessed collagen degradation in dentin matrices treated with BAC. The etch‐and‐rinse adhesive, Adper Single Bond Plus, modified with 0.5% and 1.0% BAC, was evaluated for microtensile bond strength (μTBS) and nanoleakage (NL) after 24 h and 1 yr. Thirty completely demineralized dentin beams from human molars were dipped for 60 s in deionized water (DW; control), or in 0.5% or 1.0% BAC, and then incubated in simulated body fluid (SBF). Collagen degradation was assessed by quantification of the dry mass loss and the amount of hydroxyproline (HYP) released from hydrolyzed specimens after 1 or 4 wk. Although all groups demonstrated a significant increase in NL after 1 yr, adhesive modified with 0.5% BAC showed stable bond strength after 1 yr (9% decrease) relative to the control (44% decrease). Significantly less HYP release and dry mass loss were observed for both 0.5% and 1.0% BAC relative to the control. This in vitro study demonstrates that BAC contributes to the preservation of resin–dentin bonds for up to 1 yr by reducing collagen degradation.     

Immediate and short-term effects of benzalkonium chloride on the human nasal mucosa in vivo

The in vivo effects of benzalkonium chloride, which is a preservative in most nasal sprays and drops, have been investigated in normal human volunteers. Saccharin clearance time was slightly prolonged 10 min after 0.02% benzalkonium chloride was applied, compared to that following 0.9% saline (n = 27, P = 0.04, Wilcoxon test). Sixty-five normal volunteers were randomly assigned to receive saline, fluticasone propionate aqueous nasal spray or placebo (which contained all the ingredients of fluticasone aqueous spray incl. 0.02% benzalkonium chloride, minus the fluticasone propionate) for 2 weeks, two puffs twice a day on a double-blind basis. Symptom scores, acoustic rhinometry, saccharin clearance time and ciliary beat frequency were measured immediately prior to this study and again at 2 weeks. Fifty-eight individuals completed the study with >80% compliance. There was no significant difference between the three groups in any of the variables tested. Benzalkonium chloride causes slight prolongation of mucociliary clearance shortly after application but has no detectable effect on nasal mucosal function after 2 weeks regular use.     

Benzalkonium chloride neutralizes the irritant effect of sodium dodecyl sulfate

When benzalkonium chloride (BKC), a cationic surfactant, is added to sodium dodecyl sulfate (SDS), an anionic surfactant, and used in patch testing, on the basis of their known physicochemical interaction, it is possible to predict that there will be a tendency towards a reduction in the expected irritant response when compared to SDS alone. The aim of this study was to investigate whether BKC could reduce the irritant response to SDS when applied after the SDS exposure. 54 non-atopic adult volunteers were recruited for the study. 20% SDS was applied for 2 h under occlusion. 1% BKC was then applied to the same site. Various controls, including SDS application followed by water for 2 h, were included. The irritant reaction was assessed at 24 h and 48 h. 40 of the 54 subjects had some reaction when SDS was applied for 2 h followed by either benzalkonium chloride or water control under occlusion. In comparison to water control, where BKC was applied after SDS, 20 of the 40 responders had a weaker reaction but only 4 had a stronger response. This study shows that BKC applied to skin exposed to SDS attenuates the resulting irritant reaction.     

Relationship of CD86 surface marker expression and cytotoxicity on dendritic cells exposed to chemical allergen

Human peripheral blood-derived dendritic cells (DC) respond to a variety of chemical allergens by up-regulating expression of the co-stimulatory molecule CD86. It has been postulated that this measure might provide the basis for an in vitro alternative approach for the identification of skin sensitizing chemicals. We recently reported that DC, exposed in culture to the highest non-cytotoxic concentrations of various chemical allergens, displayed marginal up-regulation of membrane CD86 expression; the interpretation being that such changes were insufficiently sensitive for the purposes of hazard identification. For the work presented here, immature DC were derived from human monocytes and treated with the chemical allergens 2,4-dinitrobenzenesulfonic acid (DNBS), nickel sulfate (NiSO4), p-phenylenediamine (PPD), Bandrowski's base (BB), hydroquinone (HQ) and propyl gallate (PG) for 48 h at concentrations which induced both no to slight to moderate cytotoxicity. For comparison, DC were treated with the irritants sodium dodecyl sulfate (SDS), benzoic acid (BA), and benzalkonium chloride (BZC) at concentrations resulting in comparable levels of cytotoxicity. CD86 expression, as measured by flow cytometry, was consistently up-regulated (ranging from 162 to 386% control) on DC treated with concentrations of chemical allergens that induced approximately 10-15% cytotoxicity. The irritants BA and BZC did not induce up-regulation of CD86 expression when tested at concentrations that induced similar levels of cytotoxicity. SDS, however, up-regulated CD86 expression to 125-138% of control in 2/4 preparations when tested at concentrations which induced similar toxicity. Our results confirm that chemical allergens up-regulate CD86 expression on blood-derived DC and illustrate further that up-regulation of CD86 surface marker expression is more robust when DC are treated with concentrations of chemical allergen that induce slight to moderate cytotoxicity.     

Severe contact dermatitis as a result of an antiseptic bath oil

Siblings aged 7 and 5 years developed extensive truncal and flexural inflammation and desquamation unresponsive to standard eczema therapy. After delays in diagnosis, subsequent history revealed prior use of an antiseptic bath oil in a much stronger concentration than recommended. The case illustrates the severe irritant contact dermatitis that can arise following inadequate dilution of antiseptic bath oils, presumably as a result of skin contact with benzalkonium chloride and triclosan. Features that may direct attention to such irritant dermatitis are flexural predominance with superficial desquamation and rapid improvement after avoidance of exposure to the antiseptic solution.     

苯扎溴铵对人精子细胞超微结构的影响

[目的 ]探讨药物苯扎溴铵对人精子细胞超微结构的影响 ,为其作为新型避孕药使用提供理论依据。 [方法 ]人精液经苯扎溴铵体外处理后 ,按扫描电镜和透射电镜样品要求处理 ,然后进行观察。 [结果 ]扫描电镜 :3 12 5 μg/ml浓度组精子的超微结构与对照组无明显差别 ,3 1 2 5 μg/ml浓度组和 3 12 5 μg/ml浓度组精子质膜破损 ,顶体脱失 ,环状沟消失 ,甚至有的精子头颈部断裂。透射电镜 :3 12 5 μg/ml浓度组精子与对照组无明显差别 ,但有少数精子的质膜有轻度破损 ,而 3 1 2 5 μg/ml浓度组和 3 12 5 μg/ml浓度组精子的质膜溶解 ,线粒体空泡样变明显 ,顶体脱落或不完整。[结论 ]苯扎溴铵主要作用于人精子细胞的质膜、顶体和线粒体 ,主要表现为质膜破损、顶体脱失和线粒体空泡样改变等     

Trabeculectomy trapdoor separation with allergic periorbital dermatitis: an unusual late-onset complication of guarded filtration surgery

Hypotony post trabeculectomy may be the result of excessive aqueous outflow. Herein a case of an elderly man with excessive filtration 2 years post trabeculectomy resulting from trapdoor separation associated with allergic periorbital dermatitis is presented. Quaternary ammonium compounds are a significant cause of allergic periorbital dermatitis. Chronic rubbing associated with allergies to multiple topical quaternary ammonium compound-containing ophthalmic preparations is likely to have contributed to the trapdoor autotrauma and separation in this man with a background of allergic contact dermatitis.     

苯扎氯铵溶液联合藻酸钙敷料治疗老年糖尿病患者足部病变的效果

目的探讨苯扎氯铵溶液联合藻酸钙敷料应用于老年糖尿病患者足部病变的治疗与护理效果。方法便利抽样法选择2009年1月至2011年9月在解放军总医院住院的老年糖尿病足部病变患者62例,采用随机数字表法将其分为对照组和观察组各31例,对照组采用常规聚维酮碘消毒后使用硫酸庆大霉素加入小剂量普通胰岛素冲洗伤口、纱球隔离、纱布包扎的方法;观察组则在对照组的基础上增加使用苯扎氯铵溶液足部浸泡5～10min,再用藻酸钙敷料隔离覆盖伤口。观察两组患者足部伤口的愈合时间、愈合效果、护理换药耗时等,并比较患者对糖尿病足护理的满意度。结果两组患者足部伤口的愈合时间、愈合效果、换药耗时以及患者对糖尿病足护理满意度比较,差异均有统计学意义(均P<0.01)。结论苯扎氯铵溶液联合藻酸钙敷料应用于老年糖尿病患者的早期足部病变,能有效缩短足部伤口愈合时间、提高伤口愈合效果、减少护理人员换药总耗时,并明显提高患者的满意度,是适宜老年糖尿病患者足部病变的良好换药方法。