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Limited Penetration (limited + penetration)
Selected AbstractsAdaptive responses to antimicrobial agents in biofilmsENVIRONMENTAL MICROBIOLOGY, Issue 8 2005Barbara Szomolay Summary Bacterial biofilms demonstrate adaptive resistance in response to antimicrobial stress more effectively than corresponding planktonic populations. We propose here that, in biofilms, reaction-diffusion limited penetration may result in only low levels of antimicrobial exposure to deeper regions of the biofilm. Sheltered cells are then able to enter an adapted resistant state if the local time scale for adaptation is faster than that for disinfection. This mechanism is not available to a planktonic population. A mathematical model is presented to illustrate. Results indicate that, for a sufficiently thick biofilm, cells in the biofilm implement adaptive responses more effectively than do freely suspended cells. Effective disinfection requires applied biocide concentration that increases quadratically or exponentially with biofilm thickness. [source] Self-reported prevalence and awareness of metabolic syndrome: findings from SHIELDINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 8 2008S. J. Lewis Summary Purpose:, This study assessed awareness of metabolic syndrome and evaluated health knowledge, attitudes and behaviours of respondents at risk. Methods:, Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD), a longitudinal US population-based survey initiated in 2004, included respondents, , 18 years of age, reporting a diagnosis of metabolic syndrome. Prevalence of metabolic syndrome was compared in SHIELD and National Health and Nutrition Examination Survey (NHANES) 1999,2002 survey. The proportion of SHIELD respondents who had heard of and/or understood metabolic syndrome was estimated. Respondents at high risk for metabolic syndrome were stratified into attitude-behaviour categories of ,Already Doing It', ,I Know I Should' and ,Don't Bother Me' and differences in attitudes and behaviours were evaluated with chi-square tests. Results:, Prevalence of reported metabolic syndrome was 0.6% in SHIELD screening questionnaire respondents (n = 211,097) vs. 25.9% in NHANES (n = 10,780). Less than 15% of SHIELD baseline questionnaire respondents (n = 22,001) had heard of or understood metabolic syndrome. Attitudes toward health status were more favourable in the ,Doing' group (27% reported fair/poor health) compared with those in the ,Should' (38%) and ,Don't' (54%) groups (p < 0.0001). The ,Don't' group was most likely to prefer medications to lifestyle change (13% vs. 2,4%) compared with ,Should' and ,Doing' groups (p < 0.0001). More ,Doing' respondents (79%) than ,Should' (59%) and ,Don't' (48%) respondents reported exercising regularly (p < 0.0001). Conclusions:, The lack of knowledge about metabolic syndrome reported in SHIELD indicates limited penetration of this concept into public awareness. With behaviour categories, respondents who report healthy attitudes are more likely to embrace lifestyle changes, while respondents who do not care may be more difficult to treat. [source] The use of topical calcineurin inhibitors in lupus erythematosus: an overviewJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 1 2008U Wollina Abstract Lupus erythematosus (LE) shows a broad range of cutaneous symptoms, including acute, subacute and chronic lesions. The gold standard of established topical treatment consists of medium- to high-potency corticosteroids. Because face and neck are often involved, adverse effects of prolonged corticosteroid use are not uncommon. There is a need of steroid-free topical treatment in LE. With the development of topical calcineurin inhibitors, tacrolimus and pimecrolimus, there is an alternative available. The present study reviews the literature data on topical tacrolimus and pimecrolimus for malar rash, subacute lesions and discoid chronic lesions among others. The present data argue for an efficacy of these compounds in acute and subacute cutaneous LE manifestations with a rapid response and only minor side-effects when used as an adjunct to systemic treatment. In chronic discoid LE, hypertrophic plaques do not well respond because of limited penetration. The primary target seems to be the decrease or blocking of cytokine production by activated T lymphocytes. [source] Use of microelectrodes to investigate the effects of 2-chlorophenol on microbial activities in biofilmsBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2005Hisashi Satoh Abstract In order to assess the applicability of using microelectrodes as a tool for inhibition tests, temporal and spatial inhibitory effects of 2-chlorophenol (2-CP) on O2 respiration and nitrification activities in municipal wastewater biofilms were investigated using microelectrodes for O2 and NH. The time-course microelectrode measurements demonstrated that 2-CP inhibited O2 respiration and nitrification activities within 6,18 min. The microbial activities were inhibited only in the upper 400 ,m of the biofilms by 2-CP, and the bacteria present in the deeper parts of the biofilms were still active, probably due to limited penetration of 2-CP. These results could reasonably explain the difference in inhibitory ratios of the O2 respiration and nitrification activities in the biofilms. O2 respiration activity was incompletely inhibited, which was attributed to the presence of O2 respiration activities in the deeper parts of the biofilm. In contrast, nitrification activity was significantly inhibited because ammonia-oxidizing bacteria were present in the upper parts of the biofilm. These results indicate that the microelectrodes with a very quick response time and a high spatial resolution are useful tools to study temporal and spatial inhibitory effects of inhibitors on in situ microbial activities in biofilms. © 2005 Wiley Periodicals, Inc. [source] | |||||||||||||