Contact dermatitis from beryllium in dental alloys

An increasing number of metals with the potential to cause allergic contact dermatitis have found their way into dental alloys for economic and practical reasons. 2 patients are reported who developed gingivitis adjacent to the Rexillium III alloy in their dental prostheses. Patch testing demonstrated positive reactions to beryllium sulfate, a component of the alloy. Components of dental alloys and the mechanism of the contact dermatitis are discussed.     

The epidermal response to subepidermal inflammation

A marked degree of hyperproliferation and hyperplasia of the epidermis secondary to experimentally induced inflammation in the corium was induced in the flank skin of guinea pigs. The substances used to evoke a granulomatous inflammation were beryllium oxide and carrageenan. The epidermal response to this subepidermal process was studied autoradiographically and it was found that the epidermal reaction was similar to that found after direct epidermal trauma such as stripping of the horny layer. It is assumed that dermal factors are responsible for initiating this epidermal reaction and their possible nature is briefly discussed.     

A metallurgical approach to metal contact dermatitis

It is well-known that some metals/alloys are sensitizing on skin contact, but it is not so well appreciated that sensitization is dependent on the reaction of the metal/alloy with sweat. The first step in skin sensitization by metals/alloys is a corrosion process and the formation of soluble metal ions. The nature of this process has implications with respect to occurrence of metal contact dermatitis, to testing techniques and to classification of metals/alloys as skin sensitizers.     

单纯疱疹病毒2型DNA疫苗对豚鼠抗病毒感染的研究

目的 探讨单纯疱疹病毒2型DNA疫苗的抗病毒感染效应.方法 重组DNA疫苗pcgD免疫雌性豚鼠,采用血清中和实验检测抗体,单纯疱疹病毒2型(HSV-2)sav株接种豚鼠,观察DNA疫苗保护动物抵抗HSV-2病毒感染的能力.结果 pc-gD免疫豚鼠产生的中和抗体效价远远高于对照组和生理盐水组,感染病毒后,表现出初发感染推迟,复发感染的严重程度下降.结论 DNA疫苗能有效地保护动物免受HSV-2病毒的攻击,延缓初发感染,减少复发感染.     

Methyl groups as antigenic determinants in skin sensitisation

The methylating agents, methyl dodecane sulphonate, methyl hexadecane sulphonate and methyl hexadec-3-ene sulphonate are strong skin sensitisers, cross-reactive with one another, in guinea pig adjuvant tests. Differences in potency are observed among these 3 compounds, and the possible reasons for this are discussed. Isoeugenol fails to elicit a sensitisation response when challenged onto guinea pigs sensitised to methyl dodecane sulphonate, indicating that the mechanism of isoeugenol sensitisation is not based on methyl transfer. It is proposed that, in skin sensitisation involving small haptenic groups, antigenic specificity is directed not against the haptenic groups but against portions of the carrier protein whose configuration has been modified as a result of the carrier-hapten reaction. This concept is supported by published data on cross-reactivity patterns with enantiomeric pairs of alpha-methylene-gamma-butyrolactone derivatives.     

Epidermal cell proliferation following an active arthus reaction in the guinea pig

Active Arthus reactions were provoked by injections of 100 micrograms horseradish peroxidase (HRP), 10 micrograms HRP and 100 micrograms bovine serum albumin (BSA) into the skin of sensitized guinea pigs. Labeling indices (LI) of epidermal basal cells were measured 1, 4, 8, 24, 48 and 72 h later by the in vivo 3H-thymidine labeling technique, and compared with those obtained with injections of antigens into the skin of non-sensitized guinea pigs. From 1-8 h after the induction of an active Arthus reaction, the LI of epidermal basal cells of the skin injected with 100 micrograms HRP decreased to a remarkably low value. On the other hand, those obtained with the reaction against 10 micrograms HRP were significantly high. At 24 h after the reaction, LI were as high as those obtained in non-sensitized guinea pigs with control intradermal injections, though the former persisted high until 48 h after the injection. In addition, decreased LI of the epidermal basal cells were observed in the skin 4 h after intradermal injections of immune complexes. It was suggested that DNA synthetic activity of the epidermis increases in a mild active Arthus reaction, while the activity may be suppressed in a severe active Arthus reaction up to 8 h after provocation.     

Detection of keratinolytic proteinase in skin tissues from guinea pigs infected with Microsporum canis by an immunoperoxidase technique

An immunoperoxidase technique was performed to detect keratinolytic proteinase (KPase) in sections of the skin taken from guinea pigs infected with Microsporum canis and in cultured M. canis using polyclonal antisera to purified KPase. Of tissue samples from guinea pigs infected with M. canis, all sections of erythematous lesions showed positive staining mainly in the horny layer and the hair follicles. Positive depositions were seen only at the level of the outer and inner root sheaths of the hair follicles in sections of skin lesions showing scales and crusts. However, sections from areas of alopecia following desquamation of the crust showed no depositions of bright red reaction products. The patterns of deposition of KPase according to the clinical course of experimental dermatophytosis were consistent with the existence of organisms observed by PAS and methenamine silver stains. These results suggest that KPase may be produced during infection with M. canis after the development of erythema and before desquamation of the crust.     

血红素氧合酶-1对豚鼠银屑病样模型外周血中TNF-α和IL-10水平的影响

目的观察血红素氧合酶-1(heme oxygenase-1,HO-1)对银屑病豚鼠模型细胞因子IL-10和TNF-α的影响。方法通过外涂普萘洛尔在豚鼠耳部诱发银屑病样的皮损及病理变化,构建银屑病豚鼠模型。将模型鼠分为5组(n=10),在模型建立24h后,给予豚鼠腹腔内注射HO-1的特异性诱导剂-钴原卟啉(cobalt protoporphyrin, CoPP)来上调HO-1的表达, CoPP剂量分别为2. 5mg/kg, 5mg/kg, 10mg/kg和20mg/kg,并设0. 9%NaCl为对照组。观察银屑病样皮损的组织病理学变化,通过免疫组化染色和免疫印迹检测动物耳部标本中HO-1蛋白的表达和定位,采用ELISA法测定动物血清中IL-10和TNF-α的水平。结果普萘洛尔外涂诱发了动物银屑病样表现,腹腔内注射CoPP显著缓解了银屑病样的病理学变化,诱导了HO-1蛋白的表达,同时使动物血清中TNF-α的水平下降、IL-10水平上升,并与CoPP的剂量呈依赖性。结论 HO-1可以调节具有银屑病样皮损的动物体内细胞因子的分泌,这可能是其抗银屑病的机制之一。     

Allergic contact dermatitis from di-isodecyl phthatate in a polyvinyl chloride identity band

An animal model for the evaluation of skin protective creams against chemical irritants is described. The irritants were applied daily for 2 weeks to shaved back skin of young guinea pigs: sodium tauryl sulphate (5% aq.: 30 min), sodium hydroxide (0,5% aq.; 2 min). and toluene (20′i. eth.; 2 mint. “The harrier cream was applied 2 h prior to and immediately after exposure to the irritant. Control animals were treated with the irritant only. The irritant reaction was scored on a 4–point scale for erythema and quantified with regard to transepidennal water loss (TEWL) by evaporime-try and skin blood flow volume (BFV) by laser Doppler velocimetry. A total of 90 guinea pigs, consisting of” individual panels of 5 to 10 animals, was tested. While one barrier cream (Slokoderm) significantly suppressed the irritation due 10 sodium lauryl sulphate and toluene, the other (Contra-Alkalh failed to do so and even aggravated the response, which was particularly evident with sodium hydroxide. This model may be useful in developing more effective barrier creams.     

Efficacy of skin barrier creams

An animal model for the evaluation of skin protective creams against chemical irritants is described. The irritants were applied daily for 2 weeks to shaved back skin of young guinea pigs: sodium tauryl sulphate (5% aq.: 30 min), sodium hydroxide (0,5% aq.; 2 min). and toluene (20'i. eth.; 2 mint. "The harrier cream was applied 2 h prior to and immediately after exposure to the irritant. Control animals were treated with the irritant only. The irritant reaction was scored on a 4–point scale for erythema and quantified with regard to transepidennal water loss (TEWL) by evaporime-try and skin blood flow volume (BFV) by laser Doppler velocimetry. A total of 90 guinea pigs, consisting of" individual panels of 5 to 10 animals, was tested. While one barrier cream (Slokoderm) significantly suppressed the irritation due 10 sodium lauryl sulphate and toluene, the other (Contra-Alkalh failed to do so and even aggravated the response, which was particularly evident with sodium hydroxide. This model may be useful in developing more effective barrier creams.     

D & C Yellow Nos. 10 and 11: delayed contact hypersensitivity in the guinea pig

D & C Yellow No. 11 was found to be a skin sensitizer in guinea pigs at an elicitation concentration of 10.0% in ethanol but not at 1.0 and 3.0%. Sensitization was induced with a 50% suspension in ethanol. D & C Yellow No. 10, the disodium salt of the mono and disulfonic acids of D & C Yellow No. 11, was not a skin sensitizer nor was it capable of eliciting a response in the D & C Yellow No. 11-sensitized guinea pigs even at a challenge concentration of 10%. Two commercial products, a soap containing 0.015% D & C Yellow No. 11 and a shampoo containing 0.002% D & C Yellow No. 10 did not elicit a reaction in the D & C Yellow No. 11-sensitized guinea pigs.     

Studies of new short-period method for delayed contact hypersensitivity assay in the guinea pig

A new method for delayed contact hypersensitivity assay of chemical compounds in guinea pigs, a short-period method (14 days) with a high detection sensitivity, has been developed. The new method was as follows; a combination of a Freund's complete adjuvant (FCA, undiluted) intradermal injection and a 24–h occusive patch on a guinea pig was performed 2x at an interval of 4 days and challenged by non-occlusive topical application II days after the first sensitization (with benzyl alcohol during test development). Acanthosis and spongiosis in the epidermis and mononuclear cell infiltration into the dermis were observed histopathologically at the skin reaction site. This newly developed method (adjuvant and 24–h occusive patch 2 test: AP2 test) could equally and/or better detect the allergenicities of 6 other chemical compounds (bromostyrol, citronellal, benzyl salicyfate. p -aminobenzoic acid ethyl ester, phenylenediamine and formaldehyde) as compared with the cumulative contact enhancement test (CCET) and the guinea pig maximization test (GPMT).     

中药槲皮素对皮肤增色作用的动物实验研究

目的研究槲皮素对豚鼠表皮中黑素细胞的影响,观察外用槲皮素对实验动物的安全性和疗效,为白癜风等色素减退性皮肤病的中药治疗提供实验依据。方法用槲皮素乙醇提取液外涂豚鼠背部皮肤并予红外线照射,5周后对涂药皮肤和对照皮肤进行活检。用不同的染色方法分别制备病理切片,观察黑素细胞形态学改变,统计给药后表皮病理切片中黑素细胞数目和黑素含量。结果豚鼠表皮外用槲皮素后黑素细胞数目明显增加,槲皮素实验组多巴阳性黑素细胞数及含黑素颗粒细胞数均较空白对照组显著增多,与阳性对照组8-甲氧补骨脂素(8-MOP)差异无显著性。结论槲皮素对棕黄色豚鼠背部皮肤有增色作用,具有促进黑素细胞增殖和黑素合成的功能。     

Relative cross reactivity of habanin, lepromin and tuberculin in guinea pigs sensitized with homologous and heterologous mycobacteria

An atypical strain Mycobacterium habana has been studied for its antigenic cross reactivity with delayed type of hypersensitivity responses in guinea pigs. Guinea pigs sensitized with M. habana, M. leprae and M. tuberculosis when challenged with habanin, lepromin and tuberculin in criss-cross fashion have demonstrated strong cross reactivity with each other. Possibilities of developing M. habana as a vaccine against tuberculosis and/or leprosy has been discussed.     

甘草酸软膏治疗豚鼠慢性湿疹模型的实验研究

目的 观察甘草酸软膏抗炎、止痒和对豚鼠慢性湿疹的治疗作用。方法 雄性昆明种小鼠、雌雄昆明种小鼠、白色豚鼠各60只,分别随机分为模型对照组（10只）、基质对照组（10只）、醋酸地塞米松乳膏组（10只）、甘草酸软膏高（10只）、中（10只）、低（10只）剂量组,各组分别建立二甲苯致小鼠耳廓肿胀模型,右旋糖酐40致小鼠搔抓模型,以及2,4-硝基氯苯反复刺激的慢性湿疹豚鼠模型,分别观察甘草酸软膏对小鼠耳廓肿胀和搔抓反应以及慢性湿疹豚鼠耳廓肿胀的影响。结果 甘草酸软膏高、中剂量可以抑制二甲苯致小鼠耳廓肿胀（P < 0.05或0.01）;甘草酸软膏高剂量可以延长右旋糖酐致小鼠搔抓的潜伏期,甘草酸软膏高、中、低剂量可减少搔抓次数（P < 0.05或0.01）,减轻慢性湿疹豚鼠模型耳廓的肿胀（P < 0.05或0.01）,并对耳廓皮肤的病理改变有一定的改善作用。结论 甘草酸软膏对慢性湿疹豚鼠模型有一定的治疗作用。     

复方酮康唑喷膜对豚鼠湿疹模型的实验研究

目的　观察复方酮康唑喷膜对豚鼠湿疹模型的疗效。方法　选择健康雌性豚鼠25只,每只背部剃毛4处,应用卵清蛋白(OVA)为抗原,激发豚鼠皮肤变态反应制备湿疹模型。将制备的模型随机分为A,B,C,D和E五组(N=100,n=20)。激发后给药,其中A,B,C组给予含高、中、低浓度地塞米松的复方酮康唑喷膜,D组给予地塞米松止痒霜,E组空白对照。根据形态学和组织病理学观察进行疗效评估。结果　豚鼠皮肤显示湿疹样皮损特点,组织病理呈湿疹样改变。药效学结果显示治疗1周时,A,B,C,D四组红斑、水肿评分和总分均明显降低(P<0. 05),而E组无明显变化。复方酮康唑喷膜与地塞米松止痒霜疗效一致,但给药次数明显减少。四组抑制率均在50%左右,B组抑制率最高,表明该组处方比较优化。结论　复方酮康唑喷膜能快速地抑制真皮炎症反应和变态反应性湿疹形成。     

Experimental nickel sensitization in the guinea pig: comparison of different protocols

3 different sensitization protocols were compared for inducing delayed-type nickel contact hypersensitivity in guinea pigs. Open epicutaneous sensitization (OE) induced nickel allergy in 11/22 (50%) guinea pigs. When intradermal injections of Freund's complete adjuvant into the nickel-painted skin was added to the same protocol. 4/13 (31 %) became sensitized. The guinea pig maximization protocol induced nickel allergy in only 7/31 (23%) of the animals. Compared with the 2 other methods, animals sensitized with open epicutaneous applications reacted more rapidly (maximum at 6 h) and strongly (2+ reaction in 12/22 of animals) in previous patch lest sites upon systemic (i p.) nickel challenge. Open epicutaneous sensitization of guinea pigs should he a useful model for studying cellular and immunological mechanisms in nickel contact sensitivity.     

性激素对豚鼠表皮郎格罕细胞及变应性接触性皮炎的影响

观察了性激素对豚鼠表皮郎格罕细胞及变应性接触性皮炎(ACD)的影响。五组豚鼠分别皮下注射麻油、雌二醇、黄体酮、丙酸睾丸酮及外用丙酸睾丸酮。二周后作表皮LC计数。用两酸睾丸酮的两组豚鼠表皮LC数较前三组明显减少(P<0.01).同时各组动物用DNCB致敏。激发前一周各组仍继续使用上述药物。二周后激发ACD,丙酸睾丸酮的两组皮肤反应以及真皮内单一核细胞浸润较另三组明显轻微(P<0.01),提示丙酸睾丸酮可抑制豚鼠的ACD.     

Contact allergy to beryllium chloride: report of 12 cases

Background. Isolated cases of allergic contact dermatitis, gingivitis and stomatitis caused by beryllium have been previously reported. We have been able to study a series of 12 patients with patch test reactions to beryllium chloride. Objectives. The study was aimed at defining the clinical and patch testing characteristics in this group of patients, and determining whether some were delayed elicitation reactions or late reactions of active sensitizations by patch testing. Material and methods. We performed a 5‐year retrospective study of patients tested with a metal series, and studied a subgroup who showed reactions to beryllium chloride. Results. A total of 1799 patients were patch tested, 62 of whom were also tested with a specific metal series; 12 of them reacted to beryllium chloride. Eight of the 12 patients showed reactions to other metals. Based on the time of positive reaction to beryllium chloride, three patterns emerged: (i) 3 patients showed positive reactions on D2–D4; (ii) 6 patients showed positive reactions between D7 and D10; and (iii) 3 patients showed positive reactions later than D10. Conclusions. Contact allergy to beryllium chloride may not be as unusual as the literature suggests. In order to avoid undetected contact allergies, we recommend performing later readings, between D7 and D10, whenever patch testing is performed with beryllium chloride. Active sensitization may occur.     

Cross-reactivity to palladium and nickel studied in the guinea pig.

In recent years there have been several reports on concomitant patch test reactions to palladium and nickel, which belong to the same group in the periodic table. Exposure to palladium mainly takes place via dental alloys and jewelry. However, the clinical relevance of simultaneous reactivity to these metals is unknown. To elucidate the question of cross-reactivity, guinea pigs were induced with palladium or nickel and simultaneously challenged with palladium and nickel. Animals sensitized to palladium according to the guinea pig maximization test method (GPMT) or to a new method by van Hoogstraten & Scheper (H&S) reacted to palladium as well as to nickel. On the other hand, animals sensitized to nickel according to H&S reacted to nickel but not to palladium. The GPMT shows that palladium is a more potent sensitizer than nickel: could palladium be the primary sensitizer in humans?