OBJECTIVES: Maintaining the constant exposure to hydrophobic organic compouds in acute toxicity tests is one of the most difficult issues in the evaluation of their toxicity and corresponding risks. Passive dosing is an emerging tool to keep constant aqueous concentration because of the overwhelming mass loaded in the dosing phase. The primary objectives of this study were to develop the constant exposure condition for an acute mortality test and to compare the performance of the passive dosing method with the conventional spiking with co-solvent. METHODS: A custom cut polydimethylsiloxane (PDMS) tubing loaded with benzyl butyl phthalate (BBP) was placed in each well of a 24-well plate containing assay medium. The rate of the release of BBP from PDMS was evaluated by measuring the change in the concentration of BBP in the assay medium. The efficiency of maintaining constant exposure condition was also evaluated using a simple two-compartment mass transport model employing a film-diffusion theory. An acute mortality test using 10 C. elegans in each well was conducted for the evaluation of the validity of passive dosing and the comparative evaluation of the passive dosing method and the conventional spiking method. RESULTS: Free concentration in the assay medium reached 95% steady state value within 2.2 hours without test organisms, indicating that this passive dosing method is useful for an acute toxicity test in 24 hours. The measured concentration after the mortality test agreed well with the estimated values from partitioning between PDMS and the assay medium. However, the difference between the nominal and the free concentration became larger as the spiked concentration approached water solubility, indicating the instability of the conventional spiking with a co-solvent. CONCLUSIONS: The results in this study support that passive dosing provides a stable exposure condition for an acute toxicity test. Thus, it is likely that more reliable toxicity assessment can be made for hydrophobic chemicals using passive dosing.
Benzophenones ; Biological Availability ; Boronic Acids ; Caenorhabditis ; Caenorhabditis elegans ; Dibutyl Phthalate ; Dimethylpolysiloxanes ; Phthalic Acids ; Solubility ; Toxicity Tests, Acute

No abstract available.
Animals ; Lichen Sclerosus et Atrophicus* ; Lichens* ; Paraphimosis*

Ichthyosis follicularis, atrichia, and photophobia (IFAP) syndrome is a rare genetic disorder caused by mutations in the MBTPS2 gene. It is characterized by ichthyosis and alopecia from birth. Photophobia may be present in infancy or early childhood. Its mode of inheritance is X-linked recessive; thus, it mostly affects male. The disease severity varies, ranging from mild cases limited to the skin to the severe variant involving multiple extracutaneous features. A 7-year-old boy presented with scanty hair on scalp and eyebrows at birth. On physical examination, scaly patches were observed on the whole body and spiky follicular hyperkeratotic papules were observed on the face and trunk. He also suffered from severe photophobia. Histopathological examination of the scalp showed miniaturized hair follicles without perifollicular fibrosis. Genetic analysis revealed a novel mutation in the MBTPS2 gene which was a homozygous missense mutation of c.245T>C leading to an amino-acid substitution from phenylalanine to serine (p.Phe82Ser). We diagnosed this patient with IFAP syndrome. To date, 25 pathogenic MBTPS2 gene mutations have been identified. To our knowledge, c.245T>C is a novel homozygous missense mutation in the MBTPS2 gene, which has not been reported in Human Gene Mutation Database, ClinVar Database, and Leiden Open Variation Database. Previous reports suggested genotype-phenotype correlations in the MBTPS2 gene mutations. Supported by a previous notion that genotype correlates with phenotype, this novel mutation can be a predictive factor for the mild form of IFAP syndrome, restricted to the classic symptom triad.

BACKGROUND: The prevalence of onychomycosis is increasing due to the recent increase of the elderly population and immunosuppressed individuals. Clinical studies on onychomycosis have been reported several times in Korea. However, the public awareness of onychomycosis has not received considerable attention, and there have been no Korean studies focused on it. OBJECTIVE: To evaluate public awareness and experience of onychomycosis in Korean. METHODS: A total of 621 participants were given questions developed for this survey. Sociodemographic characteristics, public awareness, general knowledge and experience about onychomycosis, and diagnostic and treatment behavior were surveyed. RESULTS: According to this survey, 99.5% of respondents have heard of onychomycosis, 79.4% of respondents experienced onychomycosis suspicious symptoms, and 52.8% of them responded that onychomycosis can be completely cured only by cleansing the hands and feet. The rate of self-diagnosis was 64.1% among the respondents who experienced symptoms. Only 23.9% of the respondents who were diagnosed with onychomycosis visited the hospital for the first time. Of the respondents, 54.6% who were treated at the hospital discontinued their treatments before complete cure mainly because of long treatment period. CONCLUSION Participants were well aware of onychomycosis, but the rate of self-diagnosis was high. They generally agreed to the importance of hospital treatment, but the number of patients visiting hospital was low. Moreover, people frequently discontinue their hospital treatment despite insufficient treatment duration. Patient's behaviors need to be changed, and the roles of dermatologists are important in the diagnosis, treatment, and education of the patients.

No abstract available.
Neck ; Neoplasm Metastasis ; Thyroid Gland ; Thyroid Neoplasms ; Thyroidectomy

Pyoderma gangrenosum (PG) is a neutrophilic dermatosis characterized by non-infectious ulceration of the skin. It is associated with various systemic diseases, including Takayasu arteritis (TA), rheumatoid arthritis, and inflammatory bowel disease. Notably, the co-occurrence of PG and TA is more frequent among Asians. Here, we present a rare case of TA associated with PG. A 42-year-old woman presented with recurrent ulcers affecting her legs, trunk, arms, and face, which had been refractory to various treatments for 7 years. Recently, the patient had experienced weakness in her left leg, dizziness, and a fever that had persisted for more than a month. Computed tomography angiography revealed thickening and irregularities in the common carotid arteries, right subclavian artery, and aortic arch. TA was diagnosed, following which treatment was initiated with systemic corticosteroids. It is important to consider TA in patients with PG, particularly in young women.

Cutaneous Rosai-Dorfman disease (RDD) is a rare, benign condition mainly affecting the lymph nodes and sometimes involving the skin. RDD is notorious for its poor response to medication, and surgery is often the preferred treatment option for limited lesions. Herein, we present a case of cutaneous RDD in a 49-year-old woman with multiple facial nodules that showed minimal response to treatment with steroids, isotretinoin, and methotrexate.The diagnosis of cutaneous RDD was confirmed based on histopathological examination. The patient showed minimal response to medication; however, electrosurgery resulted in a relatively good cosmetic response. The present case demonstrates that electrosurgery can be an effective treatment option for cutaneous RDD, especially in case of patients with multiple lesions. The rarity of this disease and the limited reports on its management highlights the need for further research on the efficacy of different surgical modalities for cutaneous RDD.