The gingival epithelium of the oral cavity is constantly exposed to exogenous stimuli such as bacterial toxins, allergens, and thermal changes. These exogenous stimuli are resisted by innate host defense in gingival epithelial cells. However, it is unclear exactly how the exogenous stimuli affect detrimentally on the human gingival epithelial cells. Here, we investigated whether the allergen, such as house dust mite (HDM) extract, is linked to Ca2+ signaling and proinflammatory cytokine expression in primary cultured human gingival epithelial cells. HDM extract induced an increase in intracellular Ca2+ concentration ([Ca2+]i) in a dose-dependent manner. Extracellular Ca2+ depletion did not affected on the HDM extract-induced increase in [Ca2+]i. The HDM extractinduced increase in [Ca2+]i was abolished by the treatment with U73122 and 2-APB, which are inhibitors of phospholipase C (PLC) and inositol 1,4,5-trisphosphate (IP3) receptor. Moreover, HDM extract induced the mRNA expression of pro-inflammatory cytokine, interleukin (IL)-8. These results suggest that HDM extract triggers PLC/IP3-dependent Ca2+ signaling and IL-8 mRNA expression in primary cultured human gingival epithelial cells.

This study was conducted to analyze dust mite allergen and bacterial endotoxin concentrations in the subwaycabins. For this aim, we sampled dust using a vacuum cleaner on cabin seats of subway trains operating in threeSeoul Metro Lines from April to May in 2011. The concentration of dust mite allergen and endotoxin were1,137.51±806.26ng/g and 5,742.1(4.68)EU/g, respectively. While, the concentration of dust mite allergen washigher on cabin seats of subway trains in Line B(1,487.61±930.59ng/g) than on those of trains in Lines A andC(641.9±398.3 and 1,344.9±822.4ng/g). All measurements did not exceed the National Workshop Guidelineof 2,000ng/g. While, bacterial endotoxin concentration [GM (GSD)] was higher on cabin seats of subway trainsin Line A [12,373.21(4.97EU/g)] than on those of trains in Line B and C8,520.77(3.98) and 1,631.43(1.88)EU/g. Dust mite allergen concentrations were strongly influenced by the portion of underground (on the subway line)and endotoxin concentrations were significantly correlated with the number of passengers using the subway lines.Seats for seniors and the week showed relatively higher concentrations compared to seats for general passengers.But, no significant difference of dust mite allergen and endotoxin concentrations in the subway cabins was foundrelating to seat type (p=0.451, p=0.564). There was no correlation between the dust mite allergen levels andendotoxin levels in the subway cabins (p=0.439).

An assessment was made of the toxicity of hiba, Thujopsis dolabrata var. hondai, oil and 24 oil constituents and control efficacy of four experimental spray formulations containing the oil (0.5. 1, 2, and 3% sprays) to adult American house dust mite (AHDM), Dermatophagoides farinae, and copra mite (CM), Tyrophagus putrescentiae. Results were compared with those of three conventional acaricides benzyl benzoate, N,N-diethyl-3-methylbenzamide (deet), and permethrin. Based on 24 h LC50 values, (–)-thujopsene was the most toxic constituent against AHDM (9.82 μg/cm2) and CM (10.92 μg/cm2) and the toxicity of the compound was nearly identical to that of benzyl benzoate (9.33 and 10.14 μg/cm2). High toxicity was also observed with (–)-(E)-pinocarveol, carvacrol, (+)-terpinen-4-ol, β-thujaplicin, cedrol, α-terpineol, (+)-ledene, thymol, and 2,4-di-tert-butylphenol against both mite species (LC50, 11.92–19.19 and 12.49–22.97 μg/cm2). These constituents were more toxic than deet (LC50, 35.53 and 38.42 μg/cm2). Hiba applied as 2 and 3% sprays provided >95% mortality against both mite species, whereas permethrin (cis:trans, 25:75) 2.5 g/L spray treatment resulted in ca 11% mortality. Global efforts to reduce the level of highly toxic synthetic acaricides in indoor environments justify further studies on hiba oil preparations containing the constituents described as potential contact-action fumigants or lead molecules for the control of mite populations.

House dust mite (HDM) allergens have been associated with allergic diseases, such as asthma, allergic rhinitis, and atopic dermatitis. Various acaricidal agents have been suggested for control of house dust mites; however, their remains act as allergens even after death. Therefore, for avoidance of allergen, expelling the mites is a more effective policy than killing them. In this experiment, we compared the repellent effect of two essential oils (Matricaria chamomilla, Lavandula vera) against house dust mites, Dermatophagoids farinae and D. pteronyssinus in bed fabric. The essential oils were applied by direct contact method at various doses (0.1, 0.05, 0.025, 0.0125, and 0.00625 μl/cm2 and at various exposure times (30, 60, 120, 180, and 240 min). Results of this experiment suggest that the two oils have significant repellent activity. Camomile essential oil in 0.0125 μl/cm2 at 240 minutes had a repellent effect of 93.7% and lavender essential oil in 0.05 μl/cm2 at 180 minutes had a repellent effect of 88.9%. The results of this study showed that camomile essential oil has more potent repellent activity than lavender essential oil at a particular concentration.

House dust mites (HDMs) play an important role in the occurrence of allergic diseases such as asthma and atopic dermatitis. Dermatophagoides pteronyssinus (Der p) is one of the most prevalent HDMs. It mediates the activation of T cells and monocytes, and induces the elevation of immunoglobulin E levels in allergic diseases. However, the effects of Der p on human monocytes have not been fully understood. In the present study, we investigated whether or not Der p has a great effect on the chemotactic activity of the human monocytic cell line, THP-1 cells, as induced by CC chemokines. We also show that the Der p extract (DpE) increased the chemotactic activity of THP-1 cells in response to MCP-1, RANTES, MIP-1α, and TARC, but has no effect on the expressions of CC chemokine receptors (CCRs) binding to CC chemokines in THP-1 cells. Protease inhibitors, such as aprotinin and E64, blocked the increased chemotaxis, while cytoplasmic Ca2+ influx mediated by these chemokines was inhibited by DpE. These results indicate that DpE increases the chemotactic activity of THP-1 cells in response to CC chemokines by regulating the cells’ protease-dependent mechanism. This finding may be useful in identifying the pathogenesis of allergic diseases induced by Der p.

House dust mite of the indoor environment is one of the most important causes of allergic asthma and rhinitis. It has been known that more than 70% of Korean children and about 50% of adult with the respiratory allergy are sensitive to house dust mite. The purpose of our study is to find out the relationship between the concentration of formaldehyde (HCHO)/PM10 and the number of house dust mite in the indoor environment. In this study, sampling sites were education, social and dwelling facilities. We inquire the questionnaire of the resident on the indoor air quality in all sampling sites. At the same time, we measured the concentration of formaldeh yde(HCHO)/PM10 as well as house dust mites. it was complained by 20% respondents that the indoor air quality was bad and by 10% that the atopy symptom was evident. When a certain amount of house dust mites were detected, the contents of PM10 were observed high and that of HCHO low. However when the house dust mites were not detected, the concentration of PM10 was low and that of HCHO high. From our results, it is concluded that the indoor air quality (i.e. conc. of PM10/HCHO) is quite related to the contents of house dust mites supporting the fact that the symptom of atopy and asthma is due to these small organisms.

The insecticidal potency of some essential oils have been suggested that they may find an application in the control of house dust mites. We compared the repellent effect of four essential oils ; lemon grass (Cymbopogon nardus), lavender(Lavandula vera), rosemary(Rosmarinus officinalis) and ylang ylang(Cananga odorata). The oils were exposed at different doses(0.1, 0.05, 0.025, 0.0125, and 0.00652 ㎕/㎠) and different times(1, 2, 3, 4, 5 hours) on house dust mites(Dermatophagoides farinae and D. pteronyssinus). The repellent effects(%) of essential oils that were exposed at 0.1 ㎕/㎠ and for 1 hours against house dust mites were lemon grass(63.3%) and rosemary(61%), lavender(40%), ylang ylang(40%) in the order named.

벼먼지응애는 벼 잎집 속에서 가해하기 때문에 발생 초기에는 육안으로 잎집의 변색을 판단하기 쉽지 않고, 밀도가 높아져 잎집이 변색 한 후에 발생을 알 수 있어, 수량 감소의 원인이 되고 있으나, 우리나라에서는 아직 벼먼지응애 방제방법 확립되지 않았을 뿐만 아니라, 피해정도도 알려지지 않았다. 따라서 1997년 10월 22일 파종하여 1997년 12월 2일 이앙 후 작물시험장 인공기상실에서 주간 26℃ , 야간 22℃ 의 조건에서 생육한 벼를 피해정도에 따라 조사한 결과는 다음과 같다. 1. 벼먼지응애 발생 정도에 따라 초장 및 수수는 차이가 없었으나 영화수는 감소되었다. 2.정조 변색비율은 입집의 변색정도(1-9)가 7.3인 수원 441호는 81%, 2.8인 일품벼는 18% 이었다. 3. 등숙비율은 수원 441호에서는 피해정도가 심한 IV에서는 20.4% III은 30.8%, II는 37.6% 였으며, 일품벼는 IV는 38.9%, III은 59.7%, II는 69.5% 이었다. 4. 현미 완전미율은 무피해와 대비하여 피해정도가 IV일 때 수원 441호와 일품벼의 완전미율은 비슷하였으나, III과 II에서는 수원 441호가 일품벼보다 21.0%, 15.9%가 적었다. 5. 잎집의 변색 정도와 정조의 변색 정도는 정의 상관(r=0.892), 정조의 변색 비율에 대한 등숙율과 현미수량은 부의 상관(r=-0.929, r=-0.858)이 있었다.