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Biomedical subjects

Chee-Ching Sun

Publications and source records attributed to Chee-Ching Sun.

8 recordsLinked to original sources
PubMed2006

Concomitant contact allergy to the resins, reactive diluents and hardener of a bisphenol A/F-based epoxy resin in subway construction workers.

An outbreak of suspected contact dermatitis among subway construction workers was suspected to be due to a new bisphenol A/F-based epoxy resin system (ERS). The construction workers used ERSs during the insertion of iron bars into concrete walls. The objective of the study was to determine the components (if any) of the ERS responsible for the contact allergy. Patch testing was performed on 20 of the 22 construction workers who had had contact with the ERS, and to the various subcomponents of component A on 5 of the 7 who reacted to this component. 9 patients (9/22, 40.9%) had clinical symptoms and signs of suspected contact dermatitis at presentation. 7 of these 9, but none of the 11 asymptomatic individuals, were positive to component A, while all were negative to component B. Of the 5 cases receiving further patch testing, all reacted to m-xylylene diamine, 4 to 1,6-hexanediol diglycidyl ether, 3 to epoxy resins of the bisphenol F-type and trimethylolpropane triglycidyl ether 0.25% petrolatum, and only 1 to epoxy resins of the bisphenol A-type. Contact allergy to ERSs may involve hardeners and diluents as well as resins, and patch testing for reaction to all components should be performed.

Adolescent↗
PubMed2005

Stress, insomnia, and chronic idiopathic urticaria--a case-control study.

BACKGROUND AND PURPOSE: There is growing evidence that stress might play a crucial role in the pathogenesis of urticaria. This study examined the association between chronic idiopathic urticaria and stress from major life events and explored the validity of the biopsychosocial model of stress as it relates to urticaria. METHODS: A total of 75 consecutive cases with chronic idiopathic urticaria and 133 controls with tinea pedis who visited a dermatologic clinic for treatment were recruited for participation in this study. Subjects in both groups were assessed with a semi-structured questionnaire to determine the number and subjective weighting of major life events, somatic symptoms, insomnia, irregularity of daily life, perceived family support, ego-function, positive coping, and negative coping. Structural equation modeling was used to examine the influence of biologic, psychologic, and social factors on the development of urticaria. Cluster analysis was used to classify subjects according to risk of developing urticaria. RESULTS: In the 6 months preceding disease onset, patients with chronic idiopathic urticaria had significantly more life events, higher subjective weighting of impacts from life events, more somatic symptoms, more severe insomnia, less family support, more negative coping tendencies, and were younger in age. Good ego-function, coping strategies and family support were associated with decreased frequency of urticaria. CONCLUSIONS: Stress is an important risk factor for the development of chronic idiopathic urticaria while positive coping tendencies and good family support appear to have preventative effects. Insomnia might be the most important psychosomatic symptom that is a predisposing factor for chronic urticaria.

Adaptation, Psychological↗
PubMed2004

1,2-Ethanedithiol-induced erythema multiforme-like contact dermatitis.

Contact dermatitis simulating erythema multiforme can be caused by many allergens. The chemical agent 1,2-ethanedithiol, which serves as a protective group in chemical synthesis, has hitherto only been implicated as an irritant. We report on a 22-year-old female chemistry student who developed widespread erythema multiforme-like lesions after local contact with 1,2-ethanedithiol. Many target lesions were observed bilaterally on her hands, forearms, arms, and on her forehead. One such lesion was histologically compatible with erythema multiforme. The patient had a positive patch test to 1,2-ethanedithiol, whereas none of 30 healthy subjects showed a positive reaction. However, eight of the 30 controls (26.7%) developed irritant reactions to 1,2-ethanedithiol. Cautious handling of the compound is a prudent precaution.

Adrenal Cortex Hormones↗
PubMed2004

Type IV hypersensitivity from rubber chemicals: a 15-year experience in Taiwan.

BACKGROUND: Allergic contact dermatitis from rubber chemicals is frequent but has not been reported form Asia. OBJECTIVE: To study the pattern of type IV allergy to rubber chemicals in a Chinese-based population. METHODS: A retrospective study was conducted by reviewing the patch test results of 2,235 (604 men, 1,631 women) patients from January 1986 to December 2000. RESULTS: Ninety-nine patients (4.4%) had one or more positive reactions, 42 (6.9%) men and 57 (3.5%) women. The incidence did not increase throughout the study period. Among thiuram, mercapto, carba and black-rubber mix, thiuram is the most potent sensitizer, mostly for the hand and mercapto mix for the foot. Thiuram allergy is considered occupation related, while mercapto allergy, mostly from rubber slippers, is not typically related to an occupation. A negative correlation between thiuram and carba was found despite the frequent association between these two mixes. A high risk of rubber sensitization was noted in construction, health service, transportation, agriculture and hairdressing workers. A high frequency of concomitant sensitivity to cobalt was found. CONCLUSION: This is the first statistically analyzed study of rubber chemical allergy in Asia, which supports major trends concerning rubber chemical allergy from European studies. However, wearing rubber slippers in Taiwan contributes to the high percentage of foot dermatitis. Carba should still be retained in the European standard series because of the coexistence of thiuram and carba in rubber products. The concomitant sensitization to cobalt in rubber-allergic patients needs further evaluations.

Adult↗
PubMed2003

A patch test study of 27 crude drugs commonly used in Chinese topical medicaments.

Chinese topical medicaments (CTMs) are commonly used in Taiwan and in Southeast Asia. However, a systematic evaluation of contact sensitization potential from CTM has not been carried out to our knowledge. This study was undertaken to investigate the incidence of contact sensitivity to the components of CTM in patients with contact dermatitis from CTM. A screening series of 27 crude drugs most commonly used in CTM as well as a modified European standard series was patch tested in 30 patients. The herbs with the most frequent positive reactions were Flos Caryophylli (see text), Radix Angelicae Pubescentis (see text), Cortex Cinnamomi (see text), Cortex Radix Acanthopanacis (see text), Caulis Impatientis (see text), Resina Draconis/Sanguis Draconis (see text), Fructus Cnidii (see text), Radix Gentiana Macrophyllae (see text), and Rhizoma Ligustici Chuanxiong (see text). Concomitant allergy to colophonium was found in most of these positive reactions. Reducing the concentration and simplifying the compositions of these components, as well as replacement with those of low allergenicity in CTM, such as Rhizoma Arisaematis (see text), Herba Lycopodii (see text), Radix Cyathulae Officinalis (see text), Rhizoma Pinelliae (see text), Radix Angelicae Dahuricae (see text), Herba Dendrobii (see text), Secretio Moschus (see text), and Stigmata Croci (see text), may be advocated. A precise labelling of the dosage of each component and the exact chemical compounds in CTM products could further improve the safety and therapeutic effects of CTM in the future.

Administration, Topical↗
PubMed2002

Local but not systemic administration of IFN-gamma during the sensitization phase of protein antigen immunization suppress Th2 development in a murine model of atopic dermatitis.

Biphasic Th1/Th2 development plays a central role in the pathogenesis of atopic dermatitis. In the sensitization phase after protein antigen exposure, an immune response polarized toward Th2 differentiation, which is due to the hosts' genetic proneness to the disease, initiates the skin lesions. Th1/Th2 antagonism is a potential mechanism that could be manipulated to suppress the initial Th2 deviation. IL-12 is the key cytokine for Th1 differentiation. Interferon gamma (IFN-gamma) can assist Th1 development through several mechanisms and suppress Th2 differentiation. We took advantage of a recently developed murine model of atopic dermatitis elicited by epicutaneous sensitization with protein antigen through patch application to examine the effects of different routes of IFN-gamma administration on Th1/Th2 differentiation during the sensitization phase of antigen exposure. Our data showed that systemic administration of IFN-gamma during the sensitization phase could not promote serum levels of specific IgG(2a). However, local administration (intradermal injection or patch application) of IFN-gamma during the sensitization phase could promote serum levels of specific IgG(2a) and suppress serum levels of specific IgE. Moreover, pretreatment of local IFN-gamma with protein antigen has a long-term modulatory effect on serum levels of specific IgG(2a) and IgE after repeated antigen immunization. Our results demonstrate that local but not systemic administration of IFN-gamma during the sensitization phase of protein antigen immunization could suppress the Th2 deviation in this murine model of atopic dermatitis. Thus, this may represent a novel strategy for the treatment and prevention of atopic dermatitis.

Allergens↗
PubMedDate not supplied

Percutaneous absorption of inorganic lead compounds.

The objective of this study was to determine percutaneous absorption of lead compounds, including lead sulfate, lead oxide, lead powder, and lead stearate. The lead content on the skin surface of 10 lead-battery workers was measured by the method of skin stripping, and urinary lead content of rats was measured with epicutaneous application of four lead compounds: lead sulfate, lead oxide, lead powder, and lead stearate. There were significant amounts of lead on the 9th and 10th skin strippings of the dorsal hand and the back of lead workers. The amount of lead on the dorsal hand was significantly correlated with the amount in the blood (n = 10, r 2 = 0.66, p < 0.05, linear regression). In rats, after lead compounds were applied for 12 days, total lead amount in urine significantly increased to 146.0 +/- 6.4 ng (SD) for lead stearate, 123.1 +/- 7.2 ng for lead sulfate, 115.9 +/- 5.3 ng for lead oxide, 47.8 +/- 6.9 ng for lead powder, and 10.3 ng for the control, which indicated significant skin absorption. It was concluded that significant amounts of inorganic lead compounds can be absorbed through the skin, and skin protection in lead-working or any contaminated environment should be carefully considered.

Animals↗