The Damage Pattern to the Gastrointestinal Tract Depends on the Nature of the Ingested Caustic Agent.

BACKGROUND: The mechanisms of damage to the gastrointestinal tract after caustic ingestion are conditioned by the nature of the ingested agent. Whether the nature of the ingested agent has a direct influence on patient outcomes is unknown. METHODS: From January 2013 to April 2015, 144 patients underwent emergency management for caustic injuries at the Saint Louis Hospital in Paris. There were 51 men (51 %) and the median age was 44 years [39, 48]. The ingested agents were soda-based strong alkali in 85 patients (59 %), strong acids in 36 patients (25 %), and bleach in 23 patients (16 %). Emergency and long-term outcomes were compared according to the nature of the ingested agent. RESULTS: Four patients died (3 %) and 40 patients (28 %) experienced complications. After bleach ingestion, emergency morbidity and mortality were nil, no patient required esophageal reconstruction, and functional outcome was successful in all patients. Acids were more likely to induce transmural gastric (31 vs. 13 %, p =0.042) and duodenal (9 vs. 0 %, p = 0.04) necrosis than strong alkalis, but rates of transmural esophageal necrosis were similar (14 vs. 12 %, p = 0.98). No significant differences were recorded between emergency mortality (9 vs. 1 %, p = 0.15), morbidity (33 vs. 33 %, p = 0.92), the need for esophageal reconstruction (25 vs. 20 %, p = 0.88), and functional success rates (76 vs. 84 %, p = 0.31) after acid and alkali ingestion, respectively. CONCLUSION: Bleach causes mild gastrointestinal injuries, while the ingestion of strong acids and alkalis may result in severe complications and death. Acids cause more severe damage to the stomach but similar damage to the esophagus when compared to alkalis.

Chemical processing and shampooing impact cortisol measured in human hair.

PURPOSE: The assessment of cortisol in hair has gained popularity as a means to measure retrospective hypothalamic-pituitary-adrenal activity in a number of species; however, cortisol levels from human hair subjected to typical chemicals for cosmetic or hygienic purposes may be altered by the chemicals used. The purposed of this study was to determine if exposure of hair to chemical processing or shampooing impacts cortisol values. METHODS: Human hair not exposed to prior chemical processing was cut from the posterior vertex region of the head of 106 human subjects as close to the scalp as possible. The hair sample was divided into 4-6 full-length clusters depending on quantity of hair available. Each hair sample was processed for baseline (native) cortisol and remaining clusters were exposed to five standard chemical hair treatments (Experiment 1) or were shampooed 15 or 30 times (Experiment 2). Hair was ground and cortisol levels were determined by enzyme immunoassay (EIA). Comparisons were made between native hair and processed hair using paired t-tests and Pearson correlation. RESULTS: Hair cortisol as assessed by EIA was significantly altered by chemical processing but in somewhat different ways. Exposure to bleach (harshest exposure), demi-perm (least exposure) or 15-30 shampoos resulted in a significant decrease in cortisol level while exposure to varying percentages of peroxides increased cortisol measured. There were no differences in cortisol levels associated with sex, age or tobacco use in the native hair for this particular group. CONCLUSION: Chemical processing and frequent shampooing affect cortisol levels measured in hair. Chemically processed or excessively shampooed hair should be avoided when recruiting subjects for hair cortisol studies.

Exogenous ochronosis in a Chinese patient: use of dermoscopy aids early diagnosis and selection of biopsy site.

The diagnosis of exogenous ochronosis is often challenging and requires a high index of suspicion. Herein, we report a case of exogenous ochronosis in a Chinese patient. The condition was caused by the use of bleaching agents, including creams containing hydroquinone. We demonstrate the use of dermoscopy as an invaluable tool for the early recognition of the condition, as well as in the selection of an appropriate site for a skin biopsy.

Genotoxic effect of two bleaching agents on oral mucosa.

AIM: To analyze the genotoxic effect of two hydrogen peroxide-containing bleaching products on oral mucosal cells. MATERIALS AND METHODS: The research was conducted on 22 individuals divided into two groups. Group 1 used ZOOM2 and group 2 the Opalescence BOOST bleaching agent. Specimens of the gingival and the upper lip mucosa were obtained before, immediately after, and 72 h after the bleaching procedure and were analyzed using a micronucleus test. RESULTS: Seventy-two hours after bleaching treatment with BOOST, samples collected from the oral mucosa exhibited a statistically significant increase of all genotoxicity markers, with large effect sizes (Cohen's d>0.8) observed in the total number of micronuclei (MN), number of cells with 3+ MN, karyolysis and bi-nuclear cells. ZOOM2 treatment showed a significant increase, with medium-to-large effect sizes, in the number of cells with 1 MN, karyolysis, nuclear buds and bi-nuclear cells. CONCLUSION: Both preparations demonstrated potential genotoxic effects.

Effects of bleaching agents and adhesive systems in dental pulp: a literature review

The dental pulp may be exposed to several irritants that are potentially noxious to the health and functions of this tissue. Each type of irritant or injury has different effects on the pulp, which are generally characterized by acute inflammation, chronic inflammation or necrosis. Common examples of irritants are dental caries, cavity preparation procedures, traumatic injuries, and chemical substances like bleaching agents and adhesive systems. The present study aimed to review the current knowledge about the effect of bleaching agents and adhesive systems in the human dental pulp. The review covered literature from 2004 to 2009, and only relevant manuscripts were included. Hand search of the references completed the review. Based on literature review, it may be concluded that all dental procedures associated with bleaching agents or adhesive systems involve risks to cause pulp damage. However, these risks can be minimized if the causal factors were known and avoided.

Effect of high-concentrated bleaching agents on the bond strength at dentin/resin interface and flexural strength of dentin

This study evaluated the effect of bleaching agents on bond strength at the dentin/resin interface and the flexural strength of dentin. Forty maxillary canines were selected for the study. In the shear strength test, 40 slabs of intracoronary dentin (5 x 5 mm) obtained from buccal surfaces of the crowns were included in acrylic resin. In the flexural strength test, 40 dentin bars (8 x 2 x 2 mm) were obtained from the roots. The 40 hemi-sections of the lingual surface were prepared for scanning electron microscopy (SEM). The specimens were divided into 4 groups according to the bleaching protocol (n=10): Unbleached (control), Sodium perborate + 20 percent hydrogen peroxide (SP + 20 percent HP), 37 percent carbamide peroxide (37 percent CP) and 38 percent hydrogen peroxide (38 percent HP). After 7 days, the bond strength specimens were restored and tested. Dentin bars were bleached and subjected to a three-point bending test. Data (MPa) were analyzed by ANOVA and Tukey's test (α=0.05). In the shear test, the control group was superior (p<0.05) to the bleached groups, which, in turn, were statistically similar (p>0.05). In the flexural strength test, the control group also had the highest values and differed significantly from the other groups (p<0.05). SEM revealed smear layer in all groups, with fissures in the bleached specimens. SP + 20 percent HP and 38 percent HP showed discontinuous interfaces with few tags. In conclusion, bond strength of restorative material to dentin and flexural strength of dentin were reduced after the use of high-concentration bleaching agents.

Este estudo avaliou o efeito de agentes clareadores na resistência de união da interface dentina/resina e resistência à flexão da dentina. Quarenta caninos superiores foram selecionados para o estudo. No teste de cisalhamento, 40 fragmentos de dentina intracoronária (5 x 5 mm) obtidos a partir de superfícies vestibulares das coroas foram incluídos em resina acrílica. No teste de flexão, 40 barras de dentina (8 x 2 x 2 mm) foram obtidas a partir das raízes. As 40 hemi-seções da superfície lingual foram preparadas para microscopia eletrônica de varredura (MEV). Os espécimes foram divididos em 4 grupos de acordo com o protocolo de clareamento (n=10): Não clareados (controle), perborato de sódio + peróxido de hidrogênio 20 por cento (PS + PH 20 por cento), peróxido de carbamida 37 por cento (PC37 por cento) e peróxido de hidrogênio 38 por cento (PH 38 por cento). Após 7 dias, as amostras destinadas à resistência de união foram restauradas e submetidas ao teste. As barras de dentina foram clareadas e submetidas ao teste de flexão de 3 pontos. Os dados (MPa) foram analisados por ANOVA e teste de Tukey (α=0,05). No teste de cisalhamento, o controle foi superior (p<0,05) aos grupos clareados, que foram semelhantes entre si (p>0,05). Na resistência à flexão, o grupo controle também exibiu os maiores valores, diferente dos demais (p<0,05). SEM revelou camada de smear em todos os grupos, com fissuras nos espécimes clareados. PS + 20 por cento PH e PH 38 por cento apresentaram interfaces de descontínuas com poucos tags. A resistência de união do material restaurador à dentina e a resistência à flexão da dentina foram reduzidas após o uso de agentes clareadores de alta concentração.

The prevalence of occupational asthma among denim bleachery workers in Kayseri.

The bleachery procedure is the most frequent method used to decolorize denims since sandblasting has been shown to cause silicosis. The aim of this study was to determined the prevalence of occupational asthma among denim bleachery workers in Kayseri. The study was conducted in 4 factories, in which jean bleachery was performed, in Kayseri between December 2008 and February 2009. Overall, forty-four subjects, 22 from the bleachery section and 22 from the other sections, were included. A questionnaire about respiratory symptoms was administered. Pulmonary function tests (PFTs) and serial peak expiratory flow (PEF) measurements were performed. All subjects were evaluated by posteroanterior chest x-rays. The prevalence of occupational asthma (OA) in the bleachery and other section workers was 23.8% and 9.1%, respectively (p> 0.05). Within workers, exercise dyspnea (23.3%) and wheezing (20.9%) were the most frequent symptoms. The relationship between the duration of employment and PFTs in bleachery workers (n= 21) was negatively correlated and statistically significant with FEV1, FEF25-75 (moderate; r= -0.477, -0.449, respectively; p< 0.05) and FEV1/FVC, FEV1% (well; r= -0.588, -0.509, respectively; p< 0.05). The results of the present study suggest that exposure to denim-bleaching agents plays an important role in the occurrence of respiratory symptoms, reduction in pulmonary functions, and induction of occupational asthma.

Toxic effects of skin-lightening products in Canadian immigrants.

BACKGROUND: The cultural practice of skin bleaching is highly prevalent in Africa. Most reported cases of toxic effects of skin-lightening products occur in this region. OBJECTIVE: To describe cases of misuse of over-the-counter (OTC) cosmetic skin-lightening products occurring in Canadian immigrants. METHODS: Two cases of Canadian immigrants with severe complications from OTC skin-bleaching agents were identified in a community-based dermatology practice in Toronto. The case histories were reviewed and analyzed. RESULTS: A 28-year-old African-Canadian woman developed extensive striae from long-term use of a topical cream containing clobetasol that she had purchased in a Caribbean health food store. A 55-year-old African-Canadian woman developed exogenous ochronosis from the use of a topical bleaching agent she had purchased in Ghana. CONCLUSION: Cosmetic skin lightening with unregulated topical products occurs in Canada. Dermatologists working in Canada need to be aware of this practice to provide appropriate directive care.