Although traditionally viewed as a physical barrier between the host and a variety of inhaled irritants and pathogens, it has become clear that the epithelium has a much broader functional scope. Epithelial cells are metabolically active and can play an important role in the regulation of the allergic inflammatory response. This review preview provides a consideration of the role of the epithelial cell as both a "target" for exogenous and endogenous stimuli and as an "effector" cell that is capable of producing a variety of products that can influence the inflammatory response in the airways.
Asthma* ; Epithelial Cells* ; Epithelium ; Irritants

The eye irritation potential of drug candidates or pharmaceutical ingredients should be evaluated if there is a possibility of ocular exposure. Traditionally, the ocular irritation has been evaluated by the rabbit Draize test. However, rabbit eyes are more sensitive to irritants than human eyes, therefore substantial level of false positives are unavoidable. To resolve this species difference, several three-dimensional human corneal epithelial (HCE) models have been developed as alternative eye irritation test methods. Recently, we introduced a new HCE model, MCTT HCETM which is reconstructed with non-transformed human corneal cells from limbal tissues. Here, we examined if MCTT HCETM can be employed to evaluate eye irritation potential of solid substances. Through optimization of washing method and exposure time, treatment time was established as 10 min and washing procedure was set up as 4 times of washing with 10 mL of PBS and shaking in 30 mL of PBS in a beaker. With the established eye irritation test protocol, 11 solid substances (5 non-irritants, 6 irritants) were evaluated which demonstrated an excellent predictive capacity (100% accuracy, 100% specificity and 100% sensitivity). We also compared the performance of our test method with rabbit Draize test results and in vitro cytotoxicity test with 2D human corneal epithelial cell lines.
Cornea* ; Epithelial Cells ; Humans ; Irritants ; Sensitivity and Specificity

BACKGROUND: Corrosive irritants can be defined as irritants which in provoked weak reactions or subclinical reactions induce impairment of the water barrier function and increase of transepidermal water loss (TEWL) while non-corrosive irritants can be defined as irritancy of low degree but with no increase of TEWL. Sodium lauryl sulfate (SLS) has been considered as the standard example of corrosive irritant and nonanoic acid (NAA) is an example of a noncorrosive irritant. OBJECT: This study was done to evaluate the skin irritation and recovery by corrosive and non-corrosive irritant in normal human subjects. METHODS: 0.1, 0.2, 0.5, 1, 2, 5% solution of SLS and 1, 2, 5, 10, 20, 50% solution of NAA were applied on volar forearm skin in 15 normal healthy subjects. TEWL and Erythema index (E-index) were measured at before (BL), 30 minutes (D0), 1st day (D1), 2nd day (D2), 1st week (W1), 2nd week (W2), 3rd week (W3) after the removal of the patches. RESULTS: Increase of TEWL was accelerated according to concentrations in cases of SLS, whereas increase of TEWL according to concentrations was very weak in cases of NAA. SLS induced a significantly higher TEWL increase than NAA at corresponding concentrations. In both SLS and NAA, E-index was increased according to concentrations with no difference in reaction pattern. SLS and NAA induced similar degrees of E-index at corresponding concentrations. TEWL value was highest at 30 minutes and 1 day after removal of the patch in both SLS and NAA. TEWL was recovered to baseline value at 2 weeks after removal of the patch test in case of low concentrations, at 3 weeks after removal of the patch in case of high concentrations. E-index value was highest at 30 minutes, 1 day, and 2 days after removal of the patch in both SLS and NAA. The period of recovery to baseline varied depending on the concentrations. E-index was recovered to baseline value at 1 day after removal of the patch test in case of low concentrations, and was not recovered to baseline value after 3 weeks in case of high concentrations. CONCLUSION: Corrosive irritant, SLS, showing similar degree of erythema with non-corrosive irritant, NAA, induced much more damage to stratum corneum barrier function at corresponding concentrations. Skin injuries induced by corrosive irritants would need more prolonged recovery time than skin injuries by non-corrosive irritants, and TEWL measurement would be even more sensitive than E-index measurement in case of corrosive irritants, while both TEWL and E-index measurement could be useful in case of non-corrosive irritants.
Erythema ; Forearm ; Humans ; Irritants* ; Patch Tests ; Skin* ; Sodium Dodecyl Sulfate

BACKGROUND: It is believed that certain skin types of different age, ethnic group may be more susceptible to the effect of skin irritants than others. However, some previous studies found controversies among intra-, inter-individual variation along with the possibility of ethnic differences in irritation reaction. OBJECTIVE: Thus, it is mandatory to explore the characteristics of irritant skin reaction in young and old Koreans with objective, standardized instrumental measurement techniques. METHOD: We have investigated the patterns of skin irritation between adolescent group (19 persons, average age 21.3 +/- 2.3) and old group (18 persons, average age 61.0 +/- 3.6) after physicochemical stimuli by using tape strippings (15, 30 times) and 24 hours SLS (sodium rauryl sulfate, 1% 0.5%) patch application with skin bioengineering measurements for color change(erythema index), TEWL(transepidermal water loss), capacitance and dermal microcirculation (Laser Doppler Flowmetry flux). RESULTS: The intensity of irritation represented by skin bioengineering measurements showed 30 strippings > 1% SLS > 0.5% SLS > 15 strippings, respectively. The younger the less irritation response at different time-course. TEWL, erythema index and microvascular blood distribution (LDF flux) of old group reached the plateau faster and higher than adolescent group. Occlusive patch containing water induced a potential of irritation regardless of age group that might affect early interpretation of skin bioengineering results. CONCLUSION: Intensity of irritation reaction and its kinetic suggested the role of age-dependent change of skin. The standardization on skin bioengineering measurement techniques along with irritation methods is mandatory to explore further inter-individual differences of irritation reaction in Korean.
Adolescent ; Bioengineering* ; Erythema ; Ethnic Groups ; Humans ; Irritants ; Microcirculation ; Rheology ; Skin*

BACKGROUND: As in vivo models such as animal and human tests have many potential problems the keratinocyte culture model has previously been used as an in vitro model for testing skin irritancy for common skin irritants. OBJECTIVE: To determine the skin irritant potency of several solvents, we employed cultured human keratinocytes as an in vitro model. METHODS: To evaluate the cytotoxicity of solvents, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) test, lactic dehydrogenase(LDH) release test, and tritiated thymidine incorporation test were used. RESULTS: Dose dependent decrease of cell viability and DNA synthesis, and dose dependent increase in leakage of LDH liberation were observed in normal cultured human keratinocytes after exposure to several solvents. The cytotoxicity potency of several solvents measured by each method were slightly different. CONCLUSION: These observations suggest that the cultured human keratinocyte model would be useful in evaluating the cytotoxicity of solvents.
Animals ; Cell Survival ; DNA ; Humans* ; Irritants ; Keratinocytes* ; Skin ; Solvents* ; Thymidine

BACKGROUND: As in vivo models such as animal and human tests have many potential problems the keratinocyte culture model has previously been used as an in vitro model for testing skin irritancy for common skin irritants. OBJECTIVE: To determine the skin irritant potency of several solvents, we employed cultured human keratinocytes as an in vitro model. METHODS: To evaluate the cytotoxicity of solvents, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) test, lactic dehydrogenase(LDH) release test, and tritiated thymidine incorporation test were used. RESULTS: Dose dependent decrease of cell viability and DNA synthesis, and dose dependent increase in leakage of LDH liberation were observed in normal cultured human keratinocytes after exposure to several solvents. The cytotoxicity potency of several solvents measured by each method were slightly different. CONCLUSION: These observations suggest that the cultured human keratinocyte model would be useful in evaluating the cytotoxicity of solvents.
Animals ; Cell Survival ; DNA ; Humans* ; Irritants ; Keratinocytes* ; Skin ; Solvents* ; Thymidine

BACKGROUND: Traditional visual reading of patch-test reactions is a rather subjective method, lacking the sensitivity and reproducibility needed in experimental studies. Recently the laser Doppler perfusion imaging (LDPI) has been used to measure objectively the increase in superficial blood flow which results in the appearance of erythema. OBJECTIVE: We designed this study to examine the relationship between the LDPI measurement and visual reading after patch test to several different irritants. METHODS: In this study, reading of erythema in experimentally-induced irritant contact dermatitis was performed visually and by laser Doppler perfusion imaging (LDPI). In addition, we investigated whether the LDPI measurement was appropriate in the routine patch test clinic. RESULTS: A close correlation was shown between the 2 methods (r=0.9046, p<0.001) and the LDPI producing mean adjusted perfusion values (APVs) was able to discriminate between the different visual grades. CONCLUSION: LDPI is a valuable instrument to objectively assess intensity of irritant patch-test reaction, and is indeed one of the few methods which overcomes the inter-individual variations in visual reading, but this instrument is not appropriate to use routinely in patch test clinic because of unacceptably long measurement time.
Dermatitis, Contact ; Erythema ; Irritants ; Methods ; Patch Tests ; Perfusion Imaging* ; Perfusion*

BACKGROUND: There are some variables including chamber size in irritant patch test responses. Several non-invasive bidengineering methods for quantifying and obtaining information have been developed in recent decades. OBJECTIVE: Our study was done to compare the effect of chamber size and the volume effect on the irritation potential of 1% SLS solution. METHODS: Patches with 1% sodium lauryl sulfate(SLS) solution were applied to the volar forearm of 14 healthy volunteers for 24 h. Finn chambers with 8mm(20ul), 12mm(60pl), 18mm(80ul, 200ul) inner diameters were used. Visual score and transepidermal water loss (TEWL) were measured at 30 min after removal of the patches, and every 24 h up to 4 days. RESULTS: The results are summarized as follows. 1. Visual scores were 0.18+0.32(8mm), 0.75+0.33(12mm) and 0.64+0.41(18mm) at 24 h after removal of 1% SLS and were 0.11+0.29, 0.50+0.34 and 0.25+0.26 on 4 days after removal. They were inereased 30 min and 24 h after removal and decreased towards normal 4 days after removal. By chamber size, the skin response with the large Finn chamber(12mm) increased more significantly than with the small Finn chamber(8mm). However, there were no significant differences in skin response between large and extralarge Finn chambers(18mm). 2. TEWL values were 11.86+4.09, 23.05+6.1l and 22.24+7.54g/m/h at 30 min after removal and were 9.37+2.30, 1..49+3.08 and 14.56+5.00g/m/h on 4 days after removal. They were increased 30 min after removal and decreased towards normal 4 days after removal. By chamber size, their results were the same as visual scores. 3. By visual score and TEWL, the skin response with 200pl of 1% SLS increased more significantly than 80pl in the extralarge Finn chamber. CONCLUSION: The small Finn chamber may be too small to elicit sufficient cutaneous irritation for evaluation. The large Finn chamber having larger test areas may be suitable to yield positive reactions to certain irritants. Also, the quantity of test solution per mm skin may be of importance for the skin response.
Forearm ; Healthy Volunteers ; Irritants ; Patch Tests ; Skin ; Sodium

To eat unidentified or misidentified mushrooms taken from the wild can be very dangerous. In the vast majority of toxic mushroom ingestions in Korea, the mushroom was incorrectly identified. In general, poisoning of toxic mushrooms can be classified into seven types according to the toxins that they contain; amatoxin, gyromitrin, coprine, muscarine, ibotenic acid-muscimol, psilocybin-psilocin and gastrointestinal irritants. When clinicians care for a patient who ingested a toxic mushroom, it is very important to identify what kind of mushroom may have caused a patient's illness. But, in clinical practice, accurate botanical identification of the mushroom can be very difficult. Therefore, for estimating the caused mushroom and adequate treatment of poisoning, clinicians should know the type and treatment of toxic mushroom poisoning.
Agaricales* ; Edetic Acid ; Humans ; Irritants ; Korea* ; Muscarine ; Mushroom Poisoning* ; Poisoning

Foreign body granuloma is a chronic, proliferative, inflammatory reaction caused by persistent poorly biodegradable tissue irritants. Currently, many injectable materials are being used extensively for soft tissue augmentation. Although considered biologically inert, these materials can evoke adverse reactions such as foreign body granuloma. Mainly these complications are a result of the use of unproven products injected by unlicensed or unqualified practitioners. Here we report a case of foreign body granuloma in the left lower eyelid secondary to injection of extracts from safflower seeds.
Carthamus tinctorius ; Eyelids ; Foreign Bodies ; Granuloma, Foreign-Body ; Irritants ; Seeds