Biopolymers Used for Receptor Immobilization for Nickel-Detection Biosensors in Food

Food is humans' main source of nickel intake, which is responsible for the prevalence of allergic contact dermatitis and other pathological afflictions. While robust, the classical methods for nickel detection-atomic absorption spectrometry and inductively coupled plasma mass spectrometry-are expensive and laborious; in contrast, modern methods that utilize sensors-of which most are electrochemical-have rapid run times, are cost-effective, and are easily assembled. Here, we describe the use of four biopolymers (alginate, agar, chitosan, and carrageenan) for receptor immobilization on biosensors to detect nickel ions and use an optimization approach with three biopolymer concentrations to assay analytical performance profiles. We measured the total performance of screen-printed carbon electrodes immobilized with the biopolymer-sensor combinations using cyclic voltammetry (CV). Voltammetric behavior favored the carrageenan biosensor, based on performance characteristics measured using CV, with sensitivities of 2.68 (for 1% biopolymer concentration) and 2.08 (for 0.5% biopolymer concentration). Our results indicated that among the four biopolymer combinations, carrageenan with urease affixed to screen-printed electrodes was effective at coupling for nickel detection.

Promoted mechanical properties and functionalities via Ta-tailored Ti-Au-Cr shape memory alloys towards biomedical applications

In view of the urgent demands of shape memory alloys (SMAs) for biomedical applications due to the world population aging issue, the mechanical properties and functionalities of the biocompatible Ti-Au-Cr-based SMAs, which are tailored by Ta additions, have been developed in this study. The quaternary SMAs were successfully manufactured by physical metallurgy techniques and their mechanical properties and functionalities were examined. In the continuous tensile tests, it was found that the correlation between the yielding strength and phase stability followed a typical trend of mechanical behavior of SMAs, showing the lowest yielding strength at the metastable β-parent phase. Functional mappings between the alloy strength and elongation revealed that compared to the Ta-free specimen, the ductility was promoted 50% while the strength remained intact through the 4 at.% introduction of Ta. Slight shape recovery was observed in the cyclic loading-unloading tensile tests during the unloading process and the highest shape recovery was found in the Ti-4 at.% Au-5 at.% Cr-4 at.% Ta specimen. This indicates that the 4 at.% Ta tailored Ti-Au-Cr SMAs could be a promising material for biomedical applications.

Case series of metal allergy following Nuss procedure: Not only for stainless steel bars

BACKGROUND

Pectus excavatum is often managed with the Nuss procedure. Metal allergies to pectus bars occur in 5% of patients, though pre-operative testing is not generally routine.

OBJECTIVES

This study describes our experience with pre-operative metal allergy testing and post-operative allergic reactions to pectus bars.

METHODS

A retrospective study of patients who underwent a Nuss procedure at our institution from 2010-2020 was performed. Patients with documented "metal" allergy, defined by the need for and positive response to steroid treatment and the absence of infection, were included. Data on patient characteristics and clinical course were analyzed.

RESULTS

Five of 204 patients (2.5%) identified developed allergic metal reactions. Three of five patients developed allergic reactions to titanium bars, with two requiring early removal of the bar (< 2-3 years). Four patients required more than one course of steroids, and three required debridements for skin breakdown. All patients have maintained good surgical correction at one- and three-years post removal.

CONCLUSIONS

Pectus bar metal allergies occur with both stainless steel and titanium bars. Properly selected patients for pre-operative Finn^Ⓡ Chamber testing may reduce the overall incidence of stainless-steel allergies but may miss titanium bar allergies. Early recognition and treatment of bar allergies may salvage the bar and avoid premature removal.

Chitosan self-assembled polymeric nanoparticles for percutaneous delivery of betamethasone in contact dermatitis

OBJECTIVE

The study was performed with an aim to investigate the efficiency of two treatment options in experimental nickel-induced contact dermatitis (CT), with either betamethasone or chitosan cross-linked nano-encapsulated betamethasone lanoline solutions (nano-betamethasone).

METHODS

Male Wistar rats were used. The differences were compared based on lesion visual appearance, skinfold thickness, white blood cell count (WBC), erythrocyte sedimentation rate (ESR), blood serum prooxidant-antioxidant balance (thiobarbituric acid reactive substances, TBARS; supersoxide dismutase, SOD; catalase, KAT), blood cytokine profile (TNF-α, IL-1β, IL-10, and IL-4), and histological examination of affected skin.

RESULTS

All animals treated with nickel sulfate developed CT and systemic inflammatory response on day 12, which only slightly lessened, if left untreated, on day 20. The therapeutic effectiveness of nano-betamethasone was significantly far superior (p < 0.01) compared to betamethasone. Specifically, the visual appearance of lesion severity of betamethasone vs. nano-betamethasone ± SD was 1.82 ± 0.18 vs. 1.17 ± 0.24 points, skinfold thickness-2.68 ± 0.12 vs. 2.12 ± 0.10 mm, ESR-6.38 ± 0.27 vs. 5.12 ± 0.20 mm/h, WBC-8.47 ± 0.28 vs. 7.17 ± 0.24 10⁹/L, TBARS-1.09 ± 0.04 vs. 0.94 ± 0.02 µmol/L, SOD-3.38 ± 0.26 vs. 4.12 ± 0.18 r.u./L, KAT-11.54 ± 0.14 vs. 10.02 ± 0.19 mkatal/L, respectively. The nano-betamethasone formulation was also more effective (p < 0.01) in increasing anti-inflammatory cytokines level, IL-10 (8.96 ± 0.32 vs. 7.54 ± 0.52 pg/mL) and IL-4 (13.16 ± 0.45 vs. 11.43 ± 0.58 pg/mL); and decreasing in pro-inflammatory TNF-α (20.94 ± 2.30 vs. 26.98 ± 1.16 pg/mL) and IL-1β (19.35 ± 1.28 vs. 24.77 ± 1.75 pg/mL), respectively. These findings were also supported with histological examination.

CONCLUSIONS

Nano-betamethasone may be considered as a more successful transcutaneous therapy for managing contact dermatitis compared to ointments consisting of betamethasone in traditional form.

Nickel Allergy: Epidemiology, Pathomechanism, Clinical Patterns, Treatment and Prevention Programs

Nickel is the most common cause of contact allergy in the general population and the most frequently detected allergen in patients patch tested for suspected allergic contact dermatitis (ACD). ACD from nickel is a typical type IV hypersensitivity. Nickel allergy is mostly caused by nonoccupational exposure, such as jewelry and clothing decorations, metal tools, medical devices (mainly orthopedic and orthodontic implants, cardiovascular prosthesis), eyeglasses, utensils, keys, pigment for paint, cosmetics, and food (mainly legumes, chocolate, salmon, peanuts). Occupational exposure can involve several workers (mechanics, metalworkers, platers, hairdressers, jewelers, workers in the constructions and electronic industries), classically involving hands and forearms. The classic clinical pattern of ACD caused by nickel is characterized by eczematous dermatitis involving the sites of direct contact with the metal. Non-eczematous-patterns are reported, including lichenoid dermatitis, granuloma annulare, vitiligo-like lesions, dyshidrosiform dermatitis, and vasculitis. In the case of systemic exposure to nickel, sensitized patients could develop systemic contact dermatitis. Patch testing represents the gold standard for the diagnosis of ACD from nickel. Treatment includes avoidance of contact with products containing nickel and the patient's education about the possible use of alternative products. A recent EU nickel directive, regulating the content and release of nickel from products, has caused a decrease of nickel contact allergy in some European countries. Nickel allergy is a relevant issue of public health with significant personal, social, and economic impact. This review summarizes epidemiology, pathomechanism, clinical patterns, treatment, and prevention programs.

Nickel release from metallic earrings: A survey of the Danish market and validation of the nickel spot test

BACKGROUND

Exposure to nickel-releasing ear-piercing jewellery may explain the persistently high prevalence of nickel allergy in Europe. While nickel release from earrings is regulated, field studies show that the regulation is not always respected. More knowledge is needed regarding the risk of piercing exposure including suitable screening methods.

OBJECTIVE

To examine the proportion of earrings on the Danish market that release more nickel than allowed, and to validate the use of the dimethylglyoxime (DMG) test as a screening tool.

METHODS

A total of 304 earrings were purchased and tested with the DMG test and X-ray fluorescence spectrometry. The level of nickel release was quantified in a selected subsample of 100 earrings by the European reference test EN 1811. The DMG spot test was validated against EN 1811 at different thresholds.

RESULTS

Excessive nickel release according to the European regulation was found in 45 (14.8%) tested earrings. The sensitivity of the DMG test decreased with reduced levels of nickel release (sensitivity of 45.2% at ≥0.2 μg/cm2 /week vs 61.1% at >0.5 μg/cm2 /week).

CONCLUSION

Excessive nickel release is common in earrings on the Danish market. Because of low sensitivity, the DMG test has limited use in screening of earrings for research but may still be used clinically.

Are Adverse Events Attributed to Essure Associated With Nickel Sensitization?

BACKGROUND

Essure is an effective method for hysteroscopic sterilization. Reports of adverse effects, the underlying mechanisms of which are unknown, have increased in recent years.

OBJECTIVE

The aim of the study was to determine whether there is a relationship between adverse events attributed to Essure and nickel sensitization.

METHODS

Patients presenting alleged adverse reactions to Essure were referred for nickel patch testing before removal. Data regarding medical history of nickel sensitization and symptoms attributed to Essure were collected. Dimethylglyoxime spot tests were performed on the explanted Essure. There was a follow-up at 3 months to evaluate whether there is improvement of the symptoms after Essure removal.

CONCLUSIONS

Nickel sensitization via the classic delayed hypersensitivity pathway did not seem to be responsible for adverse events attributed to Essure. Among systemic symptoms reported, extracutaneous symptoms had the highest prevalence. Systemic contact dermatitis to nickel could not be ruled out in one case.

Systemic Allergic Contact Dermatitis Due to a GORE CARDIOFORM Septal Occluder Device: A Case Report and Literature Review

Nickel hypersensitivity is a rarely reported complication of percutaneous patent foramen ovale/atrial septal defect closure. Herein, we report a case of systemic allergic contact dermatitis to nickel present in a GORE CARDIOFORM (W.L. Gore, Flagstaff, Arizona) septal occluder that resolved following explanation. To our knowledge this is the first published case of nickel hypersensitivity associated with this device. (Level of Difficulty: Beginner.)

Corrosion resistance of a Nitinol ocular microstent: Implications on biocompatibility

Nitinol is commonly used in medical implants due to its unique thermomechanical properties of shape memory and superelasticity. Free nickel has the potential to induce biological responses that may be a concern for permanent implants manufactured from nickel-containing alloys. Although there are extensive reports on the effects of surface treatments on corrosion behavior in cardiovascular Nitinol implants, there is a lack of data on corrosion resistance and impact on biocompatibility for ocular implants. Therefore, the objective of this study was to determine localized corrosion and nickel elution resistance of an electropolished Nitinol-based ocular device (Hydrus Microstent, Ivantis, Inc.) intended for patients with primary open angle glaucoma. Pitting corrosion susceptibility was characterized by potentiodynamic polarization testing per ASTM F2129. In addition, nickel ion release was quantified with immersion testing to 63 days. The results indicated high localized corrosion resistance as all samples reached polarization potentials of 800 mV without pitting initiation. Maximum nickel elution rates per device were less than approximately 1.1 ng/device/day after the first day of immersion and reduced to less than 0.1 ng/device/day after 7 days. For a patient with bilateral microstents, these nickel concentrations are ×10,000 lower than previously published tolerable intake levels for systemic toxicity. Overall, these corrosion results are in good agreement with literature values of well processed and biocompatible Nitinol devices indicating adverse systemic biological responses are not expected in vivo.

Surgical explantation of atrial septal closure devices for refractory nickel allergy symptoms

OBJECTIVES

Systemic allergic reactions to nickel alloys in percutaneous atrial septal defect occlusion devices have a poorly defined natural history. We describe our experience of surgical removal of the offending device in a series of patients with nickel allergy and refractory symptoms.

METHODS

Patients with atrial septal defect device explants for nickel allergy were reviewed. Administered questionnaires focused on symptoms, quality of life, and satisfaction along with the 36-Item Short Form Health Survey to measure physical and mental health postsurgery.

RESULTS

Atrial septal defect devices were removed for nickel allergy in 58 patients during the past 10 years. The median age was 42 years (range, 24-71 years) and 95% were women. Explantation occurred at a median of 8 years (range, 6 months-18 years) after insertion. Symptoms included fatigue (82%), chest pain (78%), headache (73%), and palpitation (58%). Surveys were available for 45 patients: 58% rated their quality of life as poor and 69% were not at all satisfied with their device. Postexplant, all patients reported improvement in their symptoms, with 18 patients (42%) noting complete resolution. In 12 patients prospectively studied, the preoperative scores in physical and mental health domains were lower than the validation group, indicating significant disability. Similarly, there was marked improvement in each domain postremoval.

CONCLUSIONS

Patients with nickel allergy and severe refractory symptoms after atrial septal defect device implantation experience profound resolution of symptoms and improved quality of life after removal. Nickel allergy should be considered before device insertion, and a low threshold should exist for surgical removal for refractory symptoms.

Metal nickel exposure increase the risk of congenital heart defects occurrence in offspring: A case-control study in China

BACKGROUND

Previous studies have investigated heavy metal exposure could increase the occurrence of congenital heart defects (CHDs). However, there are limited data regarding the relationship between exposure to nickel and CHDs occurrence in offspring. The aim of this study was to analyze the association between nickel exposure in mothers and the risk of CHDs in offspring.

MATERIALS AND METHODS

To explore the association of nickel exposure and occurrence of CHD, a case-control study with 490 controls and 399 cases with CHDs in China were developed. The concentrations of nickel in hair of pregnant woman and fetal placental tissue were measured and used a logistic regression analysis to explore the relationship between nickel exposure and risk of CHD.

RESULTS

The median concentrations of nickel were 0.629 ng/mg, P < .05 (adjusted odds ratio [aOR], 1.326; 95% CI, 1.003-1.757) and 0.178 ng/mg, P < .05 (aOR, 2.204; 95% CI, 0.783-6.206), in maternal hair and in fetal placental tissue in the CHD group, respectively. Significant differences in the level of nickel in hair were also found in the different CHD subtypes including septal defects (P < .05), conotruncal defects (P < .05), right ventricular outflow tract obstruction (P < .01), and left ventricular outflow tract obstruction (P < .05). Dramatically different nickel concentrations in fetal placenta tissue were found in cases with other heart defects (P < .05).

CONCLUSIONS

The finding suggested that the occurrence of CHDs may be associated with nickel exposure.

P2000 - A high-nitrogen austenitic steel for application in bone surgery

Optimal treatment of bone fractures with minimal complications requires implant alloys that combine high strength with high ductility. Today, TiAl6V4 titanium and 316L steel are the most applied alloys in bone surgery, whereas both share advantages and disadvantages. The nickel-free, high-nitrogen austenitic steel X13CrMnMoN18-14-3 (1.4452, brand name: P2000) exhibits high strength in combination with superior ductility. In order to compare suitable alloys for bone implants, we investigated titanium, 316L steel, CoCrMo and P2000 for their biocompatibility and hemocompatibility (according to DIN ISO 10993-5 and 10993-4), cell metabolism, mineralization of osteoblasts, electrochemical and mechanical properties. P2000 exhibited good biocompatibility of fibroblasts and osteoblasts without impairment in vitality or changing of cell morphology. Furthermore, investigation of the osteoblasts function by ALP activity and protein levels of the key transcription factor RUNX2 revealed 2x increased ALP activity and more than 4x increased RUNX2 protein levels for P2000 compared to titanium or 316 steel, respectively. Additionally, analyses of osteoblast biomineralization by Alizarin Red S staining exhibited more than 6x increased significant mineralization of osteoblasts grown on P2000 as compared to titanium. Further, P2000 showed no hemolytic effect and no significant influence on hemocompatibility. Nanoindentation hardness tests of Titanium and 316L specimens exposed an indentation hardness (HIT) of about 4 GPa, whereas CoCrMo and P2000 revealed HIT of 7.5 and 5.6 GPa, respectively. Moreover, an improved corrosion resistance of P2000 compared to 316L steel was observed. In summary, we could demonstrate that the nickel-free high-nitrogen steel P2000 appears to be a promising alternative candidate for applications in bone surgery. As to nearly all aspects like biocompatibility and hemocompatibility, cell metabolism, mineralization of osteoblasts and mechanical properties, P2000 was similar to or revealed advantages against titanium, 316L or CoCrMo.

A case of nickel allergy after endovascular aortic repair

A 78-year-old man with no history of allergy, underwent endovascular aortic repair for abdominal aortic aneurysm rupture. Postoperatively, he had low-grade fever and persistently raised white blood cell counts, but tests showed no infection. A skin rash appeared on the trunk and upper arms; we suspected a drug allergy. Despite withdrawal and/or change of medications, the symptoms remained. Finally, a patch test for nickel showed a strongly positive result. Oral prednisone 5 mg·day−1 was started, and the clinical findings resolved thereafter. No recurrence of allergy, infection, or exacerbation of the treated abdominal aortic aneurysm was noted at the 2-year follow-up.

Genotoxic and mutagenic properties of Ni and NiO nanoparticles investigated by comet assay, γ-H2AX staining, Hprt mutation assay and ToxTracker reporter cell lines

Nickel (Ni) compounds are classified as carcinogenic to humans but the underlying mechanisms are still poorly understood. Furthermore, effects related to nanoparticles (NPs) of Ni have not been fully elucidated. The aim of this study was to investigate genotoxicity and mutagenicity of Ni and NiO NPs and compare the effect to soluble Ni from NiCl2 . We employed different models; i.e., exposure of (1) human bronchial epithelial cells (HBEC) followed by DNA strand break analysis (comet assay and γ-H2AX staining); (2) six different mouse embryonic stem (mES) reporter cell lines (ToxTracker) that are constructed to exhibit fluorescence upon the induction of various pathways of relevance for (geno)toxicity and cancer; and (3) mES cells followed by mutagenicity testing (Hprt assay). The results showed increased DNA strand breaks (comet assay) for the NiO NPs and at higher doses also for the Ni NPs whereas no effects were observed for Ni ions/complexes from NiCl2 . By employing the reporter cell lines, oxidative stress was observed as the main toxic mechanism and protein unfolding occurred at cytotoxic doses for all three Ni-containing materials. Oxidative stress was also detected in the HBEC cells following NP-exposure. None of these materials induced the reporter related to direct DNA damage and stalled replication forks. A small but statistically significant increase in Hprt mutations was observed for NiO but only at one dose. We conclude that Ni and NiO NPs show more pronounced (geno)toxic effects compared to Ni ions/complexes, indicating more serious health concerns. Environ. Mol. Mutagen. 59:211-222, 2018. © 2017 The Authors Environmental and Molecular Mutagenesis published by Wiley Periodicals, Inc. on behalf of Environmental Mutagen Society.

Allergic Reaction following Implantation of a Nitinol Alloy Inferior Vena Cava Filter

A 67-year-old woman developed severe pruritus after implantation of a retrievable nitinol inferior vena cava (IVC) filter (55.4% nickel and 44.6% titanium). The pruritus resolved only after filter retrieval. The patient's hypersensitivity to nickel was confirmed by a positive skin patch test substantiating a systemic allergic reaction to the implanted nitinol IVC filter.

Molecular Mechanisms of Nickel Allergy

Allergic contact hypersensitivity to metals is a delayed-type allergy. Although various metals are known to produce an allergic reaction, nickel is the most frequent cause of metal allergy. Researchers have attempted to elucidate the mechanisms of metal allergy using animal models and human patients. Here, the immunological and molecular mechanisms of metal allergy are described based on the findings of previous studies, including those that were recently published. In addition, the adsorption and excretion of various metals, in particular nickel, is discussed to further understand the pathogenesis of metal allergy.

Safety and efficacy of medically performed tongue piercing in people with tetraplegia for use with tongue-operated assistive technology

BACKGROUND

Individuals with high-level spinal cord injuries need effective ways to perform activities.

OBJECTIVES

To develop and test a medically supervised tongue-piercing protocol and the wearing of a magnet-containing tongue barbell for use with the Tongue Drive System (TDS) in persons with tetraplegia.

METHODS

Volunteers with tetraplegia underwent initial screening sessions using a magnet glued on the tongue to activate and use the TDS. This was followed by tongue piercing, insertion of a standard barbell, a 4-week healing period, and an exchange of the standard barbell for a magnet-containing barbell. This was then used twice weekly for 6 to 8 weeks to perform computer tasks, drive a powered wheelchair, accomplish in-chair weight shifts, and dial a phone. Symptoms of intraoral dysfunction, change in tongue size following piercing, and subjective assessment of receiving and wearing a magnet-containing tongue barbell and its usability with the TDS were evaluated.

RESULTS

Twenty-one volunteers underwent initial trial sessions. Thirteen had their tongues pierced. One individual's barbell dislodged during healing resulting in tongue-tract closure. Twelve had the barbell exchanged for a magnet-containing barbell. One subject withdrew for unrelated issues. Eleven completed the TDS testing sessions and were able to complete the assigned tasks. No serious adverse events occurred related to wearing or using a tongue barbell to operate the TDS.

CONCLUSIONS

Using careful selection criteria and a medically supervised piercing protocol, no excess risk was associated with tongue piercing and wearing a tongue barbell in people with tetraplegia. Participants were able to operate the TDS.

Peripheral blood lymphocyte typing as a useful tool to objectify the oral mucosa patch test in the diagnosis of allergic contact mucositis to nickel

Nickel (Ni) exposure through the intestinal mucosa may cause a hypersensitivity reaction recently defined as allergic contact mucositis (ACM). This condition is identifiable by the oral mucosa patch test (omPT), a qualitative and subjective examination that requires clinical expertise. Our aim was to evaluate if a peripheral blood lymphocyte typing performed before and after the omPT for Ni may be able to objectify this examination for diagnostic purposes. Thirty patients with symptoms referable to the ingestion of Ni-rich foods were subjected to omPT for Ni. Before and after the omPT, each patient underwent blood sampling for the typing of total lymphocytes and their subsets (T, T helper or Th, T cytotoxic or Tc, B, natural killer or NK). Statistical analysis was performed by Student t test and receiver operating characteristic (ROC) curve analysis. According to the omPT outcomes, 18 patients were defined as Ni-sensitive and the remaining 12 as controls. In Ni-sensitive patients, the number of total, T, Th, Tc, and B lymphocytes/μL whole blood increased after the omPT (p<0.0001 for the first three, p=0.0004 and p=0.0001 for the last two lymphocyte types). No omPT-dependent lymphocyte increase was observed in controls. The post/pre omPT cell ratio, especially if calculated for Th lymphocytes, appears to be an effective index for diagnostic purposes (sensitivity=100%, specificity=83.3%, Youden index=0.833, area under curve (AUC)=0.926, p<0.0001). In conclusion, the peripheral blood lymphocyte typing with calculation of post/pre omPT cell ratio has the potential to support the omPT in diagnosing ACM, with the advantage of providing quantitative and objective data.

Immunological characterization of the allergic contact mucositis related to the ingestion of nickel-rich foods

BACKGROUND

The ingestion of nickel (Ni)-rich foods may result in allergic contact mucositis (ACM), a not yet well defined condition identifiable by oral mucosa patch test (omPT). Our aim was to characterize immunologically the ACM taking advantage from the allergen exposure that occurs during the omPT for Ni.

METHODS

Thirty-seven symptomatic patients underwent to omPT for Ni. Before and after omPT, serum and urine Ni concentrations were determined by mass spectrometry, the white blood cells were counted by hemochromocytometric assay, the peripheral lymphocyte typing was carried out by flow cytometry, total IgE and cytokine serum concentrations were measured by immunoenzymatic assays. The local lymphocyte typing was performed by immunohistochemistry only after omPT.

RESULTS

According to the omPT outcomes, 25 patients were defined as Ni-sensitive and the remaining 12 as controls. After omPT, serum and urine Ni concentrations increased significantly in all patients, while a significant increment of circulating lymphocytes and neutrophils was highlighted, respectively, in Ni-sensitive and control patients. Consistently, the Th and Tc circulating lymphocytes, as well as the Th/Tc ratio increased significantly in Ni-sensitive patients after omPT. No noteworthy increment in serum concentrations of total IgE and selected cytokines was observed in any patient after omPT. The presence of CD3+, CD4+, and CD8+ cells was highlighted on the oral mucosa biopsy samples taken from Ni-sensitive patients after omPT.

CONCLUSIONS

In patients with ACM, a local adaptive response with increased lymphocyte trafficking appears to be the most likely mechanism of reaction to Ni administered with the omPT.

High rates of metal allergy amongst Nuss procedure patients dictate broader pre-operative testing

PURPOSE

A previous study from our group estimated that as few as 2.2% of pectus excavatum patients suffered from allergy to the implanted metal bar. We sought to assess recent changes in incidence of metal allergy and identify the benefit of metal allergy testing prior to surgery.

METHODS

A retrospective review was performed of all consenting patients undergoing pectus repair during the six years between 9/2004 and 12/2010 at our institution. Incidence was based on clinical symptoms and/or T.R.U.E.® patch testing. Demographic data, history of atopy and history of metal allergy were collected. Type and number of bars used, suture site infection, skin rash and wound infection rates were reviewed.

RESULTS

Forty one of 639 patients (6.4%) had clinical or patch test evidence of metal allergy. Family history of metal allergy and pre-operative history of metal sensitivity were found to be statistically significant correlates.

CONCLUSIONS

The rate of metal allergy in the pectus excavatum population may be higher than previously reported. Patient or family history of metal allergy or metal sensitization may indicate increased risk. Metal allergy testing should be performed before Nuss procedure.

Sensitization potential of dental resins: 2-hydroxyethyl methacrylate and its water-soluble oligomers have immunostimulatory effects

The immunostimulatory effects of the representative dental resin monomer 2-hydroxyethyl methacrylate (HEMA), a HEMA derivative that does not contain a double bond (2-hydroxyethyl isobutyrate, HEIB), and polymerized water-soluble oligomers of HEMA (PHEMA) were investigated. It is known that expression levels of either or both of CD54 and CD86 in THP-1 cells are increased by exposure to sensitizing substances. In this study, the expression levels of CD54 and CD86, the production of reactive oxygen species (ROS), and the viability of the cells were measured after 24 h of incubation with these materials at different concentrations. The concentrations of the materials that induced the expression of both CD54 and CD86 were low in the following order: NiSO₄, HEMA, and methyl methacrylate (MMA). These results indicate that these dental resin monomers have lower sensitizing potentials than NiSO₄. Although HEIB, which lacks a double bond, resulted in negligible ROS production and reduced cytotoxicity than HEMA, it induced the expression of CD54 and CD86. Comparison of the results for HEMA and HEIB indicates that dental resin monomer-induced sensitization may be related not only to the oxidative stress related to the methacryloyl group but also to the structures of these compounds. Of particular interest is the result that a water-soluble PHEMA oligomer with a relatively high-molecular weight also exhibited negligible cytotoxicity, whereas the expression level of CD54 increased after exposure to PHEMA at a high concentration. This result serves as a warning that polymerized substances also have the potential to induce sensitization. This study provides insight into the nature of allergic responses to dental resin materials in clinical use and may facilitate the development of more biocompatible restorative materials in the future.

Contact alternatives to nickel

Allergic contact dermatitis to nickel is a continued health concern internationally. Nickel has been found to be the most prevalent and relevant allergen in tested populations for the last 3 decades. Furthermore, recent data from the North American Contact Dermatitis Group demonstrate positive patch-test reactions to nickel at approximately 19.5% of their tested population and a significant increase in the positivity rates for the last decade (Dermatitis. 2013;24:10-21. J Am Acad Dermatol. 1998;38:911-918). Because of the rise in allergic contact dermatitis rates to nickel, the American Contact Dermatitis Society recognized nickel to be the 2008 Allergen of the Year (J Am Acad Dermatol. 2009;60:1067-1069; Dermatitis. 2008;19:3-8). This article recognizes the importance of nickel avoidance and highlights potential alternatives.

Urinary levels of nickel and chromium associated with dental restoration by nickel-chromium based alloys

This paper aims to investigate if the dental restoration of nickel–chromium based alloy (Ni–Cr) leads to the enhanced excretions of Ni and Cr in urine. Seven hundred and ninety-five patients in a dental hospital had single or multiple Ni–Cr alloy restoration recently and 198 controls were recruited to collect information on dental restoration by questionnaire and clinical examination. Urinary concentrations of Ni and Cr from each subject were measure by graphite furnace atomic absorption spectrometry. Compared to the control group, the urinary level of Ni was significantly higher in the patient group of <1 month of the restoration duration, among which higher Ni excretions were found in those with either a higher number of teeth replaced by dental alloys or a higher index of metal crown not covered with the porcelain. Urinary levels of Cr were significantly higher in the three patient groups of <1, 1 to <3 and 3 to <6 months, especially in those with a higher metal crown exposure index. Linear curve estimations showed better relationships between urinary Ni and Cr in patients within 6-month groups. Our data suggested significant increased excretions of urinary Ni and Cr after dental restoration. Potential short- and long-term effects of Ni–Cr alloy restoration need to be investigated.

T-cell receptor (TCR) interaction with peptides that mimic nickel offers insight into nickel contact allergy

T cell-mediated allergy to Ni(++) is one of the most common forms of allergic contact dermatitis, but how the T-cell receptor (TCR) recognizes Ni(++) is unknown. We studied a TCR from an allergic patient that recognizes Ni(++) bound to the MHCII molecule DR52c containing an unknown self-peptide. We identified mimotope peptides that can replace both the self-peptide and Ni(++) in this ligand. They share a p7 lysine whose εNH(2) group is surface-exposed when bound to DR52c. Whereas the TCR uses germ-line complementary-determining region (CDR)1/2 amino acids to dock in the conventional diagonal mode on the mimotope-DR52c complex, the interface is dominated by the TCR Vβ CDR3 interaction with the p7 lysine. Mutations in the TCR CDR loops have similar effects on the T-cell response to either the mimotope or Ni(++) ligand. We suggest that the mimotope p7 lysine mimics Ni(++) in the natural TCR ligand and that MHCII β-chain flexibility in the area around the peptide p7 position forms a common site for cation binding in metal allergies.

The many faces of nickel allergy

Hypersensitivity reactions to nickel are one of the most common in the modern world. Nickel allergy prevalence is constantly growing in many countries and represents a major health and socioeconomic issue. Herein the current understanding on nickel allergy is summarized with a practical approach to the dermatologist, allergist, and general practitioner. The personal experience with some practical clinical cases of nickel dermatitis is shared. A special emphasis is put on the possible strategies for treatment and prevention of the disease.

Contact sensitivity in Behçet's disease

CONTEXT

Behçet's disease (BD) is a multisystemic inflammatory disorder with unknown etiology. Many immunological changes were reported in BD previously and these changes may affect the frequency of contact sensitivity in these patients.

OBJECTIVE

We aimed to identify whether there is an interaction between contact sensitivity and BD.

METHODS

The 'European standard series' with 27 allergens were performed on the upper backs of patients and healthy volunteers according to international standards using the IQ-Chamber. The test-units which contain these allergens were removed after 2 days. According to International Contact Dermatitis Research Group Recommendations test areas were evaluated on days 2, 3 and 7 to detect any delayed allergic reactions. The results of both groups were compared by using chi-square test.

RESULTS

One hundred adult persons (50 BDs and 50 healthy controls) were tested. Positive patch test reaction to 1 or more allergens was observed in 7 (14%) patients in BD group and in 12 (24%) persons in control group. There was no statistically significant difference between these two groups.

CONCLUSIONS

The frequency of contact sensitivity in BD is not different from healthy persons.

Allergic skin disease

The two most common allergic skin diseases in the world are often the least familiar to practicing surgeons: atopic dermatitis and contact dermatitis. When unrecognized, these disorders can cause great discomfort and decreased quality of life. This is only made worse by a surgical procedure which can exacerbate the disease process. Through proper recognition, management, and peri-surgical prophylaxis flares of these diseases can be avoided, leading to decreased morbidity and improved patient satisfaction. This article summarizes the pathophysiology and management of both atopic and contact dermatitis, with attention to implications for the surgeon.

Body piercing: complications and prevention of health risks

Body and earlobe piercing are common practices in the USA today. Minor complications including infection and bleeding occur frequently and, although rare, major complications have been reported. Healthcare professionals should be cognizant of the medical consequences of body piercing. Complications vary depending on the body-piercing site, materials used, experience of the practitioner, hygiene regimens, and aftercare by the recipient. Localized infections are common. Systemic infections such as viral hepatitis and toxic shock syndrome and distant infections such as endocarditis and brain abscesses have been reported. Other general complications include allergic contact dermatitis (e.g. from nickel or latex), bleeding, scarring and keloid formation, nerve damage, and interference with medical procedures such as intubation and blood/organ donation. Site-specific complications have been reported. Oral piercings may lead to difficulty speaking and eating, excessive salivation, and dental problems. Oral and nasal piercings may be aspirated or become embedded, requiring surgical removal. Piercing tracts in the ear, nipple, and navel are prone to tearing. Galactorrhea may be caused by stimulation from a nipple piercing. Genital piercings may lead to infertility secondary to infection, and obstruction of the urethra secondary to scar formation. In men, priapism and fistula formation may occur. Women who are pregnant or breastfeeding and have a piercing or are considering obtaining one need to be aware of the rare complications that may affect them or their child. Though not a 'complication' per se, many studies have reported body piercing as a marker for high-risk behavior, psychopathologic symptoms, and anti-social personality traits. When it comes to piercing complications, prevention is the key. Body piercers should take a complete medical and social history to identify conditions that may predispose an individual to complications, and candidates should choose a qualified practitioner to perform their piercing. As body piercing continues to be popular, understanding the risks of the procedures as well as the medical and psychosocial implications of wearing piercing jewelry is important for the medical practitioner.