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Selected AbstractsAdjunctive benefits of systemic amoxicillin and metronidazole in non-surgical treatment of generalized aggressive periodontitis: a randomized placebo-controlled clinical trialJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2005Adrian Guerrero Abstract Background: The objective of this study was to assess the adjunctive clinical effect of the administration of systemic amoxicillin and metronidazole in the non-surgical treatment of generalized aggressive periodontitis (GAP). Methods: Forty-one systemically healthy subjects with GAP were included in this 6-month double-blind, placebo-controlled, randomized clinical trial. Patients received a course of full-mouth non-surgical periodontal treatment delivered over a 24 h period using machine-driven and hand instruments. Test subjects received an adjunctive course of systemic antibiotic consisting of 500 mg amoxicillin and 500 mg metronidazole three times a day for 7 days. Clinical parameters were collected at baseline, and at 2 and 6 months post-treatment. Results: In both the test and the placebo groups, all clinical parameters improved at 2 and 6 months. In deep pockets (7 mm), the test treatment resulted in an additional 1.4 mm (95% confidence interval 0.8, 2.0 mm) in full-mouth probing pocket depth (PPD) reduction and 1 mm (0.7, 1.3 mm) of life cumulative attachment loss (LCAL) gain at 6 months. In moderate pockets (4,6 mm), the adjunctive benefit was smaller in magnitude: PPD reduction was 0.4 mm (0.1, 0.7 mm) and LCAL gain was 0.5 mm (0.2, 0.8 mm). In addition, the 6-month data showed LCAL gains 2 mm at 25% of sites in test patients compared with 16% in placebo (p=0.028). Similarly, PPD reductions of 2 mm or more were observed in 30% of sites in test and 21% of sites in placebo patients. Seventy-four percent of pockets with PPD 5 mm at baseline were 4 mm or shallower at 6 months in the test group. This compared with 54% in the placebo group (p=0.008). Disease progression at 6 months was observed at 1.5% of test and 3.3% of sites in test and placebo, respectively (p=0.072). Conclusions: These data indicate that a 7-day adjunctive course of systemic metronidazole and amoxicillin significantly improved the short-term clinical outcomes of full-mouth non-surgical periodontal debridement in subjects with GAP. [source] Evaluation of cognitively accessible software to increase independent access to cellphone technology for people with intellectual disabilityJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 12 2008S. E. Stock Abstract Background There are over two billion telephones in use worldwide. Yet, for millions of Americans with intellectual disabilities (ID), access to the benefits of cellphone technology is limited because of deficits in literacy, numerical comprehension, the proliferation of features and shrinking size of cellphone hardware and user interfaces. Developments in smart phone technology and PDA-based cellphones provide an opportunity to make the social and safety benefits of cellphones more independently accessible to this population. Method This project involved employment of universal design and other specialised software development methods to create a multimedia cellphone interface prototype which was compared with a typical mainstream cellphone in a usability evaluation for individuals with ID. Participants completed a structured set of incoming/outgoing phone tasks using both the experimental and control conditions. Usability measurements included the amount of assistance needed and errors made in completing the cellphone use sequence. Results A total of 22 individuals with ID participated in the research by engaging in a series of incoming and outgoing cellphone calls using both the multimedia cellphone prototype system and a mainstream Nokia 6360 cellphone. Test subjects required significantly less help (P = 0.001) and made significantly fewer errors (P < 0.001) when completing eight calls using the specialised multimedia phone system as compared with the mainstream phone. Conclusions The statistical evidence of both usability results provide promising evidence of the feasibility of implementing universal design and other specialised software development methodologies for increasing independent access to the benefits of cellphone technologies for students and adults with ID. Issues related to designing cognitively accessible interfaces, study limitations and future directions are discussed. [source] Impact of a regional anesthesia rotation on ultrasonographic identification of anatomic structures by anesthesiology residentsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 3 2009S. L. OREBAUGH Objective: The specific aim of this study was to determine the ability of anesthesiology residents to independently identify a series of anatomic structures in a live model using ultrasound, both before and after a 4-week regional anesthesia rotation that incorporates a standardized ultrasound training curriculum for peripheral nerve blockade. Methods: Ten CA2 and CA3 anesthesiology residents volunteered to participate in this study. Each resident was subjected to a pre-rotation practical exam, in which he attempted to identify 15 structures at four sites of peripheral nerve blockade, in a test subject. Each resident then received specific training for ultrasound-guided nerve blocks during a 4-week regional anesthesia rotation, and then completed a post-rotation exam. The mean number of structures correctly identified on the exams was compared for significant differences utilizing a paired t -test. Results: Residents were able to identify significantly more anatomic structures on the post-rotation exam as compared with the pre-rotation exam (mean 14.1 vs. 9.9, P<.001), as well as more peripheral nerve targets. The most frequently misidentified structures on the pre-rotation exam were the subclavian vein, the sciatic nerve in the popliteal fossa, and the femur. Conclusions: Ultrasound-naļve anesthesiology residents, who received instruction and experience with ultrasound-guided peripheral nerve blocks on a 4-week regional anesthesia rotation, significantly improved their ability to independently identify relevant anatomic structures with ultrasonography. [source] Ethanol-Induced Social Facilitation in Adolescent Rats: Role of Endogenous Activity at Mu Opioid ReceptorsALCOHOLISM, Issue 6 2009Elena I. Varlinskaya Background:, Ethanol consumption is considerably elevated during adolescence. Attractiveness of alcohol for humans during the adolescent developmental period is based, in part, on its ability to induce social facilitation,a facilitation of social interactions not only evident in human adolescents but also in adolescent rats. Endogenous opioid systems are among the multiple neural systems implicated in the behavioral and reinforcing effects of ethanol and may play a substantial role in modulating stimulatory effects of low doses of ethanol on social behavior during adolescence. This possibility was explored in the present study through the use of an animal model of peer-directed social behavior. Methods:, Sprague,Dawley rats were challenged early in adolescence with saline or ethanol intraperitoneally (i.p.), placed into an individual holding cage for 30 minutes, and then tested in a familiar situation with a nonmanipulated partner of the same age and sex. In Experiment 1, each test subject was injected subcutaneously with one of the three doses of a nonselective opioid antagonist naloxone (0, 0.05, and 0.1 mg/kg), 5 minutes prior to the social interaction test and 25 minutes following challenge with saline or ethanol (0.5 g/kg), whereas in Experiment 2 animals were challenged with one of the six doses of ethanol (0, 0.25, 0.5, 0.75, 1.0, and 1.25 g/kg) prior to injection of either saline or naloxone (0.05 mg/kg). In Experiment 3, animals were pretreated i.p. with the selective ,-opioid antagonist CTOP (0, 0.01, 0.025, 0.05, and 0.1 mg/kg) 30 minutes prior to challenge with saline or ethanol (0.5 g/kg). Results:, Low doses of ethanol (0.5 and 0.75 g/kg) produced social facilitation, as indexed by significant increases in play fighting and social investigation. Both doses of naloxone and the three highest doses of CTOP blocked the stimulatory effects of ethanol on play fighting but not on social investigation. These effects were not associated with alterations in ethanol pharmacokinetic properties or with shifts in the biphasic ethanol dose,response curve. Conclusions:, Ethanol-induced facilitation of social play behavior seen in adolescent animals is mediated in part through ethanol-induced release of endogenous ligands for the ,-opioid receptor or an ethanol-associated enhancement of sensitivity of these receptors for their endogenous ligands. [source] Dynamics and Rate-Dependence of the Spatial Angle between Ventricular Depolarization and Repolarization Wave Fronts during Exercise ECGANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 3 2010Tuomas Kenttä M.Sc. Background: QRS/T angle and the cosine of the angle between QRS and T-wave vectors (TCRT), measured from standard 12-lead electrocardiogram (ECG), have been used in risk stratification of patients. This study assessed the possible rate dependence of these variables during exercise ECG in healthy subjects. Methods: Forty healthy volunteers, 20 men and 20 women, aged 34.6 ± 3.4, underwent an exercise ECG testing. Twelve-lead ECG was recorded from each test subject and the spatial QRS/T angle and TCRT were automatically analyzed in a beat-to-beat manner with custom-made software. The individual TCRT/RR and QRST/RR patterns were fitted with seven different regression models, including a linear model and six nonlinear models. Results: TCRT and QRS/T angle showed a significant rate dependence, with decreased values at higher heart rates (HR). In individual subjects, the second-degree polynomic model was the best regression model for TCRT/RR and QRST/RR slopes. It provided the best fit for both exercise and recovery. The overall TCRT/RR and QRST/RR slopes were similar between men and women during exercise and recovery. However, women had predominantly higher TCRT and QRS/T values. With respect to time, the dynamics of TCRT differed significantly between men and women; with a steeper exercise slope in women (women, ,0.04/min vs ,0.02/min in men, P < 0.0001). In addition, evident hysteresis was observed in the TCRT/RR slopes; with higher TCRT values during exercise. Conclusions: The individual patterns of TCRT and QRS/T angle are affected by HR and gender. Delayed rate adaptation creates hysteresis in the TCRT/RR slopes. Ann Noninvasive Electrocardiol 2010;15(3):264,275 [source] Rapid Human-Assisted Creation of Bounding Models for Obstacle Avoidance in ConstructionCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2004J. McLaughlin A practical, interactive method for doing so is described here. The method: (1) exploits a human operator's ability to quickly recognize significant objects or clusters of objects in a scene, (2) exploits the operator's ability to acquire sparse range point clouds of the objects quickly, and then (3) renders models, such as planes, boxes, and generalized convex hulls, to be displayed graphically as visual feedback during equipment operation and/or for making proximity calculations in an obstacle detection system. Experiments were performed in which test subjects were asked to model objects of varying complexity and clutter. These models were then compared to control models using a ray-tracing algorithm to determine the operator's ability to create conservative models that are critical to construction operations. To demonstrate the applicability of the modeling method to obstacle avoidance, a scripted motion robot simulation was conducted using an artificial potential formulation that monitors position (closest point on manipulator link to nearest obstacle) as well as velocity (link inertia). Experimental results indicate that bounding models can be created rapidly and with sufficient accuracy for obstacle avoidance with the aid of human intelligence and that human-assisted modeling can be very beneficial for real-time construction equipment control. [source] Chloroatranol, an extremely potent allergen hidden in perfumes: a dose-response elicitation studyCONTACT DERMATITIS, Issue 4 2003Jeanne Duus Johansen Oak moss absolute is a long-known, popular natural extract widely used in perfumes. It is reported as the cause of allergic reactions in a significant number of those with perfume allergy. Oak moss absolute has been the target of recent research to identify its allergenic components. Recently, chloroatranol, a hitherto unknown fragrance allergen, was identified in oak moss absolute. The objective was to assess the clinical importance of chloroatranol as a fragrance allergen by characterizing its elicitation profile. 13 patients previously showing a positive patch test to oak moss absolute and chloroatranol were included, together with a control group of 10 patients without sensitization to either of the 2 materials. A serial dilution patch test was performed on the upper back with concentrations ranging from 200 to 0.0063 p.p.m. of chloroatranol in ethanol. Simultaneously, the participant performed an open test simulating the use of perfumes on the volar aspect of the forearms in a randomized and double-blinded design. A solution with 5 p.p.m. chloroatranol was used for 14 days, and, in case of no reaction, the applications were continued for another 14 days with a solution containing 25 p.p.m. All test subjects (13/13) developed an allergic reaction at the site of application of the solution containing chloroatranol. Among them, 12/13 (92%) gave a positive reaction to the 5 p.p.m. solution and 1 to 25 p.p.m. None of the controls reacted (P < 0.001). The use test was terminated at median day 4. The dose eliciting a reaction in 50% of the test subjects at patch testing was 0.2 p.p.m. In conclusion, the hidden exposure to a potent allergen widely used in perfumes has caused a highly sensitized cohort of individuals. Judged from the elicitation profile, chloroatranol is the most potent allergen present in consumer products today. [source] The Effect of Noise in the Emergency DepartmentACADEMIC EMERGENCY MEDICINE, Issue 7 2005Leslie S. Zun MD Abstract Background: It is hypothesized that high ambient noise in the emergency department (ED) adversely affects the ability of the examiner to hear heart and lung sounds. Objective: To determine the ability of various examiners to hear heart tones and lung sounds at the high end of loudness typically found in the ED setting. Methods: The study was divided into two parts. First, sound levels in the ED were measured over various times during the months of January through June 2001, using a sound level monitor. The second part of the study was the determination of the ability to hear heart and lung sounds on a young healthy volunteer using the same Littmann lightweight stethoscope at a predetermined ambient noise level of 90 dB. The results were entered into a database and analyzed using SPSS version 10 (Chicago, IL). Descriptive statistics, analysis of variance, frequencies, and correlation were calculated using this program. Results: Two hundred five sound measurements were taken in the ED during the study period in three locations at various hours. The mean noise level at the nursing station was 57.60 dB, with a minimum of 45.00 dB and a maximum of 70.00 dB. Four of the 104 test subjects (3.8%) were unable to hear the heart tones, and nine of the 104 (8.7%) were unable to hear the lung sounds. Fifty percent (27 of 54) of the test subjects reported diminished lung sounds and eight of 15 (53.3%) reported diminished heart sounds. No significant difference was found between hearing heart sounds and years of experience, age, professional position, and quality of the sound. Significant differences were found between hearing lung sounds and years of experience and professional position, but not with age, gender, and sound quality. Conclusions: This study demonstrated that most of the tested examiners have the ability to hear heart and lung sounds at the extreme of loudness found in one ED. [source] A nonlethal microsampling technique to monitor the effects of mercury on wild bird eggsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2009Katherine R. Stebbins Abstract Methylmercury is the predominant chemical form of mercury reported in the eggs of wild birds, and the embryo is the most sensitive life stage to methylmercury toxicity. Protective guidelines have been based mainly on captive-breeding studies with chickens (Gallus gallus), mallards (Anas platyrhynchos), and ring-necked pheasants (Phasianus colchicus) or on field studies where whole eggs were collected and analyzed and the effects of the mercury were measured based on the reproductive success of the remaining eggs. However, both of these methods have limitations. As an alternative, we developed a technique that involves extracting a small sample of albumen from a live egg, sealing the egg, returning the egg to its nest to be naturally incubated by the parents, and then relating the hatching success of this microsampled egg to its mercury concentration. After first developing this technique in the laboratory using chicken and mallard eggs, we selected the laughing gull (Larus atricilla) and black-necked stilt (Himantopus mexicanus) as test subjects in the field. We found that 92% of the microsampled laughing gull eggs met our reproductive endpoint of survival to the beginning of hatching compared to 100% for the paired control eggs within the same nests. Microsampled black-necked stilt eggs exhibited 100% hatching success compared to 93% for the paired control eggs. Our results indicate that microsampling is an effective tool for nonlethally sampling mercury concentrations in eggs and, as such, can be used for monitoring sensitive species, as well as for improving studies that examine the effects of mercury on avian reproduction. [source] The Space Mission MIR'97: operational aspectsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2000R. Ewald Background A German astronaut visited the MIR space station between 10 February and 2 March 1997. Together with his Russian colleagues, he conducted a series of scientific investigations before, during and after his stay aboard the MIR station. Research performed during this flight was part of a global space life sciences programme and focused on metabolic homeostasis, fluid balance, calcium homeostasis and cardiovascular regulatory mechanisms. The main goal of the scientific experiments was to use this mission as a milestone to establish international networks of scientific collaboration using space research as a tool for focused research in respective fields. Thus, in most cases the results obtained from the astronaut complemented a series of results obtained on ground and from other flights. In other cases, they extended previous results and opened new fields for future research. Participants Human space flight with astronauts serving as operators and at the same time as test subjects is very complex. Many people, including mission control, a science management team, medical operations, ethics committees and a medical board, participated to harmonize the different requirements, thus making a maximal scientific outcome possible. Conclusion In summary, this space mission may be seen as a model for focused long-term multidisciplinary international research, and demonstrates that space medicine is no longer adventure but science. [source] The porcine snout , an in vitro model for human lips?EXPERIMENTAL DERMATOLOGY, Issue 2 2005U. Jacobi Abstract:, The morphology and histology of test sites commonly used to study the penetration of lip products differ significantly from those of the human lip itself. The aim of this study was to investigate whether the porcine snout could serve as an equivalent in vitro model for human lips. The lips of human test subjects and biopsies of porcine snout tissue were compared using histological and microscopic techniques. Using a dermatological laser scanning microscope, the penetration of topically applied fluorescent sodium fluorescein was investigated in vivo on human lips and in vitro on the porcine snout. Biopsies from the in vitro experiments were studied using fluorescence microscopy. Some parts of the porcine snout show a similar morphology and histology as human lips. The stratum corneum (SC) and the epidermis of the porcine snout are thicker than those of human tissue. Both in vivo and in vitro, the topically applied fluorescent dye was detected only on the skin surface and within the uppermost SC layer. These results indicate that porcine snout can be used as an in vitro model for human lips in penetration studies. Both human and porcine tissues exhibit an efficient barrier against the penetration of topically applied substances. [source] Microbial colonization patterns predict the outcomes of surgical treatment of intrabony defectsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2006Lisa Heitz-Mayfield Abstract Aim: To explore the impact of bacterial load and microbial colonization patterns on the clinical outcomes of periodontal surgery at deep intrabony defects. Materials and Methods: One hundred and twenty-two patients with advanced chronic periodontitis and at least one intrabony defect of >3 mm were recruited in 10 centres. Before recruitment, the infection control phase of periodontal therapy was completed. After surgical access and debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full-mouth plaque scores and full-mouth bleeding scores were assessed. Microbial colonization of the defect-associated pocket was assessed using a DNA,DNA checkerboard analysis. Results: Total bacterial load and counts of red complex bacteria were negatively associated with CAL gains 1 year following treatment. The probability of achieving above median CAL gains (>3 mm) was significantly decreased by higher total bacterial counts, higher red complex and T. forsythensis counts immediately before surgery. Conclusions: Presence of high bacterial load and specific periodontal pathogen complexes in deep periodontal pockets associated with intrabony defects had a significant negative impact on the 1 year outcome of surgical/regenerative treatment. [source] Clinical outcomes following treatment of human intrabony defects with GTR/bone replacement material or access flap aloneJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2004A multicenter randomized controlled clinical trial Abstract Aim: This prospective multicenter randomized controlled clinical trial was designed to compare the clinical outcomes of papilla preservation flap surgery with or without the application of a guided tissue regeneration (GTR)/bone replacement material. Materials and Methods: One hundred and twenty-four patients with advanced chronic periodontitis were recruited in 10 centers in seven countries. All patients had at least one intrabony defect of 3 mm. The surgical procedures included access for root instrumentation using either the simplified or the modified papilla preservation flap in order to obtain optimal tissue adaptation and primary closure. After debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CALs), probing pocket depths (PPDs), recession, full-mouth plaque scores and full-mouth bleeding scores (FMBS) were assessed. Results: One year after treatment, the test defects gained 3.3±1.7 mm of CAL, while the control defects yielded a significantly lower CAL gain of 2.5±1.5 mm. Pocket reduction was also significantly higher in the test group (3.7±1.8 mm) when compared with the controls (3.2±1.5 mm). A multivariate analysis indicated that the treatment, the clinical centers, baseline PPD and baseline FMBS significantly influenced CAL gains. Odds ratios (ORs) of achieving above-median CAL gains were significantly improved by the test procedure (OR=2.6, 95% CI 1.2,5.4) and by starting with deeper PPD (OR=1.7, 1.3,2.2) but were decreased by receiving treatment at the worst-performing clinical center (OR=0.9, 0.76,0.99). Conclusions: The results of this trial indicated that regenerative periodontal surgery with a GTR/bone replacement material offers an additional benefit in terms of CAL gains, PPD reductions and predictability of outcomes with respect to papilla preservation flaps alone. [source] In vivo near-IR imaging of approximal dental decay at 1,310,nmLASERS IN SURGERY AND MEDICINE, Issue 4 2010Michal Staninec DDS Abstract Objective The high transparency of dental enamel in the near-IR (NIR) light at 1,310-nm can be exploited for imaging dental caries without the use of ionizing radiation (X-rays). We present the results of the first in vivo imaging study in which NIR images were acquired of approximal contact surfaces. Methods NIR imaging hand-pieces were developed and attached to a compact InGaAs focal plane array and subsequently used to acquire in vivo NIR images of 33 caries lesions on 18 test subjects. The carious lesions were discernible on bitewing radiographs, but were not visible upon clinical examination. Results NIR images were acquired in vivo from three directions and the majority of lesions examined were too small to require restoration, based on accepted bitewing radiograph criteria. All but one of the 33 lesions examined were successfully imaged from at least one direction. Conclusion This first in vivo study of imaging at the 1,310-nm wavelength region shows that NIR imaging has great potential as a screening tool for the detection of approximal lesions without the use of ionizing radiation. Lasers Surg. Med. 42:292,298, 2010. © 2010 Wiley-Liss, Inc. [source] Field trials on the repellent activity of four plant products against mainly Mansonia population in western EthiopiaPHYTOTHERAPY RESEARCH, Issue 3 2003Mamuye Hadis The repellent activity of essential oils of lemon eucalyptus (Eucalyptus maculata citrodion), rue (Ruta chalepensis), oleoresin of pyrethrum (Chrysanthemum cinerariaefolium) and neem (Azadiracta indica) have been ,eld tested as 40%, 50% and 75% solutions in coconut oil against populations of mosquitoes consisting mainly of Mansonia in Gambella, western Ethiopia. A latin square design was used to randomize the test subjects for possible individual differences for mosquito attraction. Repellency was evaluated as the percentage protection. Deet was included in the study for comparison. All the plant products manifested repellency. At 50% concentration at which the highest repellency was recorded the protection was 91.6%, 87.0%, 96.0%, 97.9% for rue, neem, pyrethrum and deet, respectively. The essential oil of lemon eucalyptus was not tried at this concentration. At a 40% concentration deet, lemon eucalyptus and pyrethrum were signi,cantly (p < 0.05) more effective than rue and neem. At a 50% concentration, deet and pyrethrum were signi,cantly better (p < 0.05) than rue and neem. At a 75% concentration concentration, deet and lemon eucalypus performed signi,cantly better (p < 0.05) than pyrethrum and neem. The difference between pyrethrum and neem was also signi,cant (p < 0.01). Copyright © 2003 John Wiley & Sons, Ltd. [source] Hypersensitivity symptoms associated with exposure to cellular telephones: No causal linkBIOELECTROMAGNETICS, Issue 4 2002Maila Hietanen Abstract The hypothesis that there exist hypersensitive persons who perceive subjective symptoms from radiofrequency (RF) fields emitted by hand held mobile phones (cellular phones) was tested using double blind provocation experiments. We also tested whether sensitive subjects are able to determine whether the phone is on or off by sensing RF fields. The study group consisted of 20 volunteers (13 women and 7 men) who reported themselves as being sensitive to cellular phones. The RF exposure sources were one analogue NMT phone (900 MHz) and two digital GSM phones (900 and 1800 MHz). The duration of a test session was 30 min, and three or four sessions were performed in random order for each subject during 1 day. The subjects were asked to report symptoms or sensations as soon as they perceived any abnormal feelings. In addition, the subjects' blood pressure, heart rate, and breathing frequency were monitored every 5 min. The results of the study indicated that various symptoms were reported, and most of them appeared in the head region. However, the number of reported symptoms was higher during sham exposure than during real exposure conditions. In addition, none of the test persons could distinguish real RF exposure from sham exposure. Hence, we conclude that adverse subjective symptoms or sensations, though unquestionably perceived by the test subjects, were not produced by cellular phones. Bioelectromagnetics 23:264,270, 2002. © 2002 Wiley-Liss, Inc. [source] Methyldibromoglutaronitrile in rinse-off products causes allergic contact dermatitis: an experimental studyBRITISH JOURNAL OF DERMATOLOGY, Issue 1 2004C.D. Jensen Summary Background The frequency of sensitivity to the cosmetic preservative methyldibromoglutaronitrile (MDBGN) has increased significantly in Europe. Most cases of allergic contact dermatitis from MDBGN are caused by leave-on cosmetic products. The risk of developing allergic contact dermatitis from rinse-off products has been less studied. Objectives To investigate the allergic response elicited in presensitized individuals from exposure to a rinse-off product preserved with the maximum permitted level of MDBGN. Methods Nineteen contact allergic individuals and nine controls participated in a double-blind, randomized repeated open application test (ROAT) using two coded liquid soaps with and without MDBGN. Areas of 50 cm2 on the lower arms were washed with the soaps twice a day for up to 28 days; two of the subjects continued for 34 days. The subjects were also patch tested with a dilution series of MDBGN to determine their patch test threshold values. Results Seven presensitized individuals (37%) developed allergic contact dermatitis from the soap containing MDBGN. The mean dose of MDBGN per application was 2·2 µg cm,2 and the reactions appeared between days 6 and 34. All nine controls had negative ROATs. The difference in reactivity between test subjects and controls was significant (one-sided Fisher's exact test, P = 0·04). Patch test threshold values ranged from <,0·001% to 0·2% MDBGN in ethanol/water. Conclusions This study shows that the exposure to a rinse-off product containing the maximum permitted level of MDBGN can easily elicit an allergic response in presensitized individuals. Along with reported cases of induction and elicitation caused by MDBGN in rinse-off products the study indicates that the permitted level of MDBGN in rinse-off products is too high. We recommend that this level should be re-evaluated. [source] HLA DPB1*0201 allele is negatively associated with immunoglobulin E responsiveness specific for house dust mite allergens in TaiwanCLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2000Background House dust mite (HDM) Dermatophagoides pteronyssinus is the most important source of indoor allergens that cause allergic diseases in Taiwan. We prepared purified HDM allergens (Der p 1, Der p 2 and Der p 5) to detect allergen-specific immunoglobulin (Ig) E responsiveness among a large number of test subjects. The robust genetic typing system for HLA class II genes also facilitated the study on association of HLA and allergic response toward HDM. Objective This study intended to investigate the association between HLA class II alleles and the IgE responsiveness to the major allergens from HDM, D. pteronyssinus. Methods Two hundred and forty-eight subjects were selected for HLA association study. Plasma HDM allergen (Der p 1, Der p 2, Der p 5) -specific IgE and Der p 2-specific IgG antibodies were detected by ELISA, while HLA class II -DRB1, -DQA1, -DQB1, -DPB1 genetic polymorphism was determined by polymerase chain reaction/sequence-specific oligonucleotide probe hybridization (PCR/SSOPH). Statistical comparison of the allelic distribution of each HLA class II genes among the individuals with/without HDM allergen-specific IgE and IgG antibodies were performed. Results There was no significant association between HLA DRB1, DQB1, DQA1 alleles and HDM-specific IgE responsiveness noted. Only DRB1*0803 and the linked DQA1*0103 alleles showed positive association with Der p 5-specific IgE responsiveness. However, we found that HLA-DPB1*1301 predisposed subjects to IgE responsiveness to HDM Der p 5. HLA DPB1*0501 was weakly associated with the IgE responsiveness to HDM Der p 1 and Der p 5. There was a strong negative association between the HLA-DPB1*0201 allele with IgE responsiveness to Der p 1 (OR: 0.30, P , 0.0001, P , 0.0007, Pc , 0.010). Conclusion We clearly observed the association between HLA DPB1 alleles and specific IgE responsiveness to HDM major allergens. The molecular mechanism of HLA-DPB1*0201 involvement in protecting subjects from HDM-specific IgE responsiveness awaits further investigation. [source] | |||||||||||||