Even the reported results also suffered from the same deficiency

Even the reported results also suffered from the same deficiency in that samples used to detect AHLs were obtained from an open lake, which certainly contained numerous other AHL-producing bacteria. Only in 2008 did Sharif et al. show for

the first time that the cyanobacterium Gloeothece could produce C8-AHL QS signal in selleck chemical axenic culture. In this study, M. aeruginosa PCC-7820 was cultured axenically during the whole growth period and was tested for the presence of other microorganisms periodically by microscopic observation and culture detection on LB plates. Other microorganisms were not found in these two detection methods throughout the M. aeruginosa growth process. Therefore, it is the first report to detect the production of AHLs in the cyanobacterium M. aeruginosa in axenic cultures by both bioreporters assay and LC-MS technique. The bioassay strain C. violaceum CV026 has high sensitivity to short-chain unsubstituted AHLs such as C4-AHL and C6-AHL, but not C8-AHL or longer,

while A. tumefaciens KYC55 has the broadest range of AHL detection including short-chain, long-chain, substituted, and unsubstituted AHLs (Steindler & Venturi, 2007). Vibrio harveyi BB170 is another type of bioreporter that is applied widely to detect AI-2-like molecules (DeKeersmaecker & Vanderleyden, 2003). Based on the characteristics of the three bioreporters and the results of the biosensors assay, A. tumefaciens KYC55 showed a positive reaction but C. violaceum Sotrastaurin datasheet CV026 and V. harveyi BB170 did not; we suggest that M. aeruginosa could synthesize AHL-like molecules with long acyl side chains. Moreover, the concentration of these signaling molecules increased in a density-dependent manner and reached

its highest concentration of 18 nM relative to the reference OOHL when the cell density was about 1.03 × 107 cells mL−1, 30 days after inoculation (Fig. 1). Such concentration Selleckchem Staurosporine might be sufficient to trigger a QS-related response in M. aeruginosa. However, the AHLs concentration of M. aeruginosa declines sharply at day 30 when the alga moves to the late growth phase (Fig. 1). Similar phenomenon has been observed in other bacteria such as A. tumefaciens, Erwinia carotovora, and Xanthomonas campestris, the QS signal of the bacteria accumulates in early stationary phase and its level subsequently declines sharply when bacteria move into stationary phase (Barber et al., 1997; Holden et al., 1998; Zhang et al., 2002). This phenomenon might be controlled by quorum-sensing signal-turnover systems in the bacteria (Zhang et al., 2002) or AHLs alkaline hydrolysis with the pH increase in the cultures (Gao et al., 2005).

We identified three segments of the carotid arteries on which to

We identified three segments of the carotid arteries on which to conduct the measurements, the common carotid artery (1 cm proximal to the bifurcation), the carotid bulb (in the bifurcation) and the internal carotid artery (1 cm distal to the bifurcation). Far wall CIMT images were obtained and digitalized for each patient [31]. The median value of the measurements obtained in the three segments PTC124 was used in the

statistical analyses. The presence of subclinical atherosclerosis was defined as a median CIMT >0.8 mm or the presence of a plaque. A plaque was defined as a thickness >1.5 mm or a focal structure that encroaches into the arterial lumen by at least 0.5 mm, or 50% of the surrounding CIMT value [32]. We used the χ2 test or Fisher’s exact Y-27632 datasheet test to evaluate the associations between categorical variables. The κ coefficient was used as

a measure of the agreement between the presence of subclinical atherosclerosis and the CVD risk calculated by the FRS. Means for variables with a normal distribution were compared using analysis of variance (anova) and the Kruskall–Wallis test was used for variables with nonnormal (skewed) distributions. When significant differences among CVD risk groups were found, pair-wise comparisons were performed between the groups representing the three levels of CVD risk. Post hoc analyses included the Bonferroni test. Logistic regression analysis was used to study the variables associated with the presence of subclinical atherosclerosis (as a binary variable) in the group of patients with low CVD risk as stratified by FRS (i.e. risk <10%). Variables included in the multivariate

analyses were age, gender, smoking status, systolic blood pressure (SBP), diastolic blood pressure (DBP), glucose, LDL cholesterol, HDL cholesterol, triglycerides, Urease BMI, HIV-1 basal viral load, basal CD4 cell count, lipodystrophy, exposure time to nucleoside reverse transcriptase inhibitor (NRTI), nonnucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitor (PI) treatments, inflammatory markers, and oxidative markers. Statistical analyses were performed with the spss 17.0 statistical package (SPSS, Chicago, IL, USA). A significant difference was defined as two-tailed P<0.05. We observed a low level of agreement between the stratification of CVD risk measured using the FRS and the presence of subclinical atherosclerosis measured using CIMT (Table 1). Of note is the finding that a high number of patients who did have subclinical atherosclerosis were classified as having a low CVD risk using the FRS score (n=66; 56.4%). Table 2 summarizes the data on the patients stratified into three groups according to the presence of atherosclerosis, but with a low or high CVD risk according to the FRS. The group of patients with a high CVD risk according to the FRS and with atherosclerosis were older (P<0.

; 1 g/d for 10 d), and oral tramadol (200 mg/d) Complete remissi

; 1 g/d for 10 d), and oral tramadol (200 mg/d). Complete remission was observed 6 weeks later. Human envenomation caused by gastropods of the genus Conus is well known, although

only Trametinib mouse very few cases were reported in the literature.1,2 Divers and shell collectors are most frequently involved. Genus Conus (C.) includes more than 500 species. Cone shells are widely distributed in the Indo-Pacific. They may be found in shallow waters, under rocks, and along coral reefs.1 Cone species most frequently responsible for human envenomation are Conus geographus and Conus striatus. Other potentially dangerous species are Conus aulicus, Conus gloriamaris, Conus marmoreus, and C textile. Systemic symptoms and signs of cone envenomation include weakness, numbness, paraesthesia, ptosis, diplopia, aphonia, nausea, dysphagia, difficulty swallowing, acute anuria, dyspnoea, respiratory failure, absent reflexes, muscular paralysis, hypotension, and cardiac failure.1,2 Deaths occurred in India, Japan, Fiji Islands, Vanuatu Islands, New Caledonia, and Australia. It is estimated that

15% to 25% of all stings caused by C geographus are fatal.2 Death may be very rapid. Worst prognosis is in children. Skin lesions are often located on the hands and feet. Stinging or burning sensation or pain are initial symptoms.2 However, cone sting may be asymptomatic. Swelling, ischemia, cyanosis, CH5424802 price localized paraesthesia, and numbness are common.1,2 Pruritus is rare.1 Treatment of cone envenomation is symptomatic. Hot packs or immersion of the affected area in hot water can Flavopiridol (Alvocidib) be helpful. There

is no antivenom. Prevention is based on the use, by divers and shell collectors, of thick protective gloves. In this patient, as well as in another case we recently observed,3 the development of a cutaneous abscess was probably caused by the hot-humid climate, that facilitated multiple bacterial superinfections, and the application of several, unnecessary topical drugs. Skin and soft tissue bacterial infections are an emerging problem in travelers returning from tropical and subtropical countries. According to the results of a clinical and bacteriological study recently published,4 impetigo (35% of patients) and abscess (23%) are the two most frequent bacterial diseases of the skin. Lower limbs (75% of patients) are especially involved. Insect bites and stings are significantly associated with impetigo and ecthyma. Methicillin-susceptible S aureus (43% of patients), Group A Streptococcus (34%), and an association of both bacteria (23%) were isolated. Considering that methicillin-resistant S aureus is emerging worldwide, susceptibility tests should be always performed in travelers returning from tropical and subtropical countries with skin and soft tissue infections. The authors state they have no conflicts of interest to declare. “
“Two Japanese travelers from Bali were diagnosed with murine typhus in Japan during the same period.

The target emtricitabine AUC0-24 was ≥7 mg h/L or ≤30% reduction

The target emtricitabine AUC0-24 was ≥7 mg h/L or ≤30% reduction from the typical AUC of 10 mg h/L in nonpregnant historical controls. Each subject’s Selleck Ku 0059436 physician had the option to change the dose based on the pharmacokinetic results. A stopping criterion to trigger an evaluation of the adequacy of drug exposure was predefined as six of 25 women (24%; exact 80% confidence limits: 13%, 38%) falling below the target AUC. The goal was to prevent excess accrual to a cohort

with known inadequate antiretroviral exposure. Once pharmacokinetic sampling had been completed for all subjects, antepartum and postpartum emtricitabine exposure measurements for each woman were compared using a repeated measures design. For the comparison of third-trimester versus postpartum emtricitabine exposure, the comparisons were made at the within-subject level, using 90% confidence limits for the geometric

mean ratios of antepartum to postpartum pharmacokinetic parameters. When the true geometric mean of the ratio (the antilog of the true mean of the log ratios) of the pharmacokinetic parameters for pregnant and nonpregnant conditions has a value of 1, this indicates equal geometric mean pharmacokinetic parameters for the pregnant Selleck LDK378 and nonpregnant conditions. If the 90% confidence intervals (CIs) are entirely outside the limits (0.8 and 1.25), the pharmacokinetic exposure parameters for the pregnant and nonpregnant conditions are considered different.

If, however, the 90% Miconazole CIs are entirely within the limits (0.8, 1.25), the drug exposures are considered equivalent. If the 90% CIs overlap with (0.8, 1.25), these data alone do not support any conclusions. The magnitudes of the differences in the median values of pharmacokinetic parameters antepartum and postpartum were also assessed with the Wilcoxon signed-rank test. Descriptive statistics, including geometric least-squares means and 90% CIs, were calculated for pharmacokinetic parameters of interest in each study period. Twenty-six participants taking emtricitabine were enrolled in P1026s. All 26 women completed antepartum pharmacokinetic sampling and 22 completed postpartum sampling. The clinical characteristics of the study subjects are summarized in Table 1. The target emtricitabine exposure was AUC ≥7.0 mg h/L, for a ≤30% reduction from typical exposure for nonpregnant historical controls. Fifteen of 26 subjects (58%; 80% CI 45–70%) achieved this target during pregnancy. The 11 subjects with AUCs below the target remained on the standard dose of 200 mg once daily. The antepartum concentration versus time curves for each subject are shown in Figure 1. Twenty-one of 22 subjects (95%; 80% CI 89–100%) achieved the AUC target postpartum. The postpartum concentration versus time curves for each subject are shown in Figure 2.

However, it is not precisely known which species of microorganism

However, it is not precisely known which species of microorganisms play the principal part in these beneficial properties. Some major buy Vorinostat health benefits of probiotics and their proposed mechanisms are illustrated in Table 1. Several probiotic bacteria have been introduced in the market, and the range of products in which probiotic bacteria are added is increasing (Table 2).

Some of the major health attributes of probiotics are discussed in the following sections. Resistance to enteric pathogens Antagonism activity Adjuvant effect increasing antibody production Systemic immune effect Colonization resistance Limiting access of enteric pathogens (pH, bacteriocins/defensins, antimicrobial peptides, lactic acid production, and toxic oxygen metabolites) Aid in lactose digestion Bacterial lactase acts on lactose in the small intestine Small bowel IDH inhibitor bacterial overgrowth Lactobacilli influence the activity of overgrowth flora, decreasing toxic metabolite production Normalization of a small bowel microbial community Antibacterial characteristics Immune system modulation Strengthening of nonspecific and antigen-specific

defense against infection and tumors Adjuvant effect in antigen-specific immune responses Regulating/influencing Th1/Th2 cells, production of anti-inflammatory cytokines Decreased release of toxic N-metabolites Anticolon cancer effect Antimutagenic activity Detoxification of carcinogenic metabolites Alteration in pro-cancerous enzymatic activity of colonic microorganisms Stimulation

of immune function Influence on bile salt concentration Decreased detoxification/excretion of toxic microbial metabolites Increased bifidobacterial cell counts and shift from a preferable protein- to carbohydrate-metabolizing microbial community, less toxic and for putrefactive metabolites, improvements of hepatic encephalopathy after the administration of bifidobacteria and lactulose Prevention of antigen translocation into blood stream Prevent excessive immunologic Sorafenib order responses to increased amount of antigen stimulation of the gut Blood lipids, heart disease Assimilation of cholesterol by bacterial cell Alteration in the activity of BSH enzyme Antioxidative effect Bacterial peptidase action on milk protein results in antihypertensive tripeptides Cell wall components act as ACE inhibitors Adhesion to urinary and vaginal tract cells Competitive exclusion Inhibitor production (H2O2, biosurfactants) Infection caused by Helicobacter pylori Competitive colonization Inhibition of growth and adhesion to mucosal cells, decrease in gastric H.

Thus, the conditioning

of media with spent culture supern

Thus, the conditioning

of media with spent culture supernatants or cell-free extracts derived from helper strains has been used for the growth stimulation of species such as Catellibacterium spp., Psychrobacter spp., Sphingomonas spp. and Symbiobacterium spp. (Tanaka et al., 2004; Bae et al., 2005; Kim et al., 2008a, b; Nichols et al., 2008). Signalling molecules may be responsible for such growth promotion. Empirical testing of known signal molecules, cyclic AMP (cAMP) and acyl homoserine lactones was shown to significantly increase the cultivation efficiency of marine bacteria (Bruns et al., 2002) – the addition to liquid media of 10 μM cAMP led to cultivation efficiencies of up to 100%. This remarkable result has not, however, been corroborated by other studies investigating the effect AZD0530 clinical trial of cAMP on the growth of individual species. Coppola et al. (1976) observed a growth

inhibition of Escherichia coli in media supplemented with 5 mM cAMP, and in a study by Chen & Brown (1985), the addition of cAMP at levels ranging from 0.01 to 100 μM showed no consistent influence on the growth rates of Legionella pneumophila. A cAMP concentration-dependent effect on growth may explain the differences in the results of the various studies. It is also possible that use of the most-probable-number CX 5461 method in the study by Bruns et al. (2002) led to an overestimation Cobimetinib order of cell numbers.

Another study (Nichols et al., 2008), in this case investigating the growth stimulation of a Psychrobacter strain, successfully characterized the growth-promoting factor responsible and identified this as a 5-amino-acid peptide. An alternative approach for the culture of as-yet-uncultivated organisms is to simulate their natural environment in vitro. Kaeberlein et al. (2002) constructed a diffusion chamber that allowed the passage of substances from the natural environment (intertidal marine sediment) across a membrane and successfully grew bacteria from marine sediment that were previously uncultivated. These bacteria were subsequently cultured on solid media, but grew only in the presence of other bacteria, implying codependency. Similar diffusion chambers have been constructed since, to culture ‘uncultivable’ or rarely cultivated bacteria from marine (Nichols et al., 2008) and freshwater environments (Bollmann et al., 2007). The latter study reported a significantly greater diversity of recovered isolates using the diffusion chamber than on conventional agar plates. Also mimicking the natural environment, sterile fresh- (Stingl et al., 2008; Wang et al., 2009) and marine- (Rappe et al., 2002; Song et al., 2009) waters have been used to culture previously uncultivated bacteria. Ben-Dov et al.

Accordingly, VCX1 overexpression provides only a moderate increas

Accordingly, VCX1 overexpression provides only a moderate increase in Cd2+ resistance ( Pittman et al., 2004). In view of the dual participation of Cod1p in the unfolded protein response (UPR) and Ca2+ homeostasis (Cronin et al., 2002), their up-regulation in the three mutant selleck chemicals strains (Fig. 3C–H) could point to ER stress induced by Cd2+. Indeed, it was recently suggested that Cd2+ accumulation in the ER of yeast activates the UPR pathway which, in turn, is

essential to protect the strains against the metal presence (Gardarin et al., 2010). New studies are necessary to confirm these hypotheses regarding YVC1, VCX1 and COD1 responses to Cd2+ in yeast. Besides participation of Ca2+-transporters in Cd2+ tolerance, the results of this work also point to the interference of Cd2+ with Ca2+ homeostasis in yeast cells. Indeed, several reports have been demonstrated that Cd2+ treatment is able to increase the intracellular Ca2+ concentration in mammalian cells. Notably, the raise

in cytosolic Ca2+ seems to be associated with the signaling to Cd2+-induced apoptosis (Lee et al., 2006, Liu et al., 2007 and Wang et al., 2007). In S. cerevisiae, Cd2+ also stimulates the entry of Ca2+ into the WT cells, which appears to be an important aspect of its toxicity ( Kessels Rucaparib et al., 1987 and Gardarin et al., 2010). A phenotypic characteristic of pmr1Δ mutant is the increase in the basal concentration of Ca2+ cytosolic ( Locke et al., 2000) and, in contrast with this website WT strain, Cd2+-treatment promotes decrease in Ca2+ levels in these cells ( Lauer-Júnior et al., 2008). Interestingly, our results about expression of intracellular Ca2+-transporters genes showed that in WT strain Cd2+ affect only the expression of PMC1, while in pmr1Δ

cells it is responsible by a general up-regulation of genes associated with Ca2+ transport. This could indicate that reduction of Ca2+ levels in pmr1Δ after Cd2+ treatment requires a more accurate adjustment than the probable augment of Ca2+ in WT cells, which could be minimized by the own up-regulation of PMC1. However, this hypothesis needs experimental confirmation. Genes whose deletion produces a great sensitivity to a specific metal are considered primary elements in detoxification pathways, while genes that reply through alteration in the expression profile possibly are downstream elements in the same pathway or elements of alternative routes to detoxification (Jin et al., 2008). This work suggests that Pmr1p and Pmc1p can contribute, along with Ycf1p, to Cd2+ detoxification in S. cerevisiae. The high sensitivity of ycf1Δ to Cd2+ confirms that Ycf1p is the main line of defense against Cd2+ ions. However, Pmr1p and Pmc1p can act as ancillary pathways that help yeast to cope with Cd2+ toxicity especially when function of Ycf1p is compromised, even though pmc1Δ and pmr1Δ mutants are not highly sensitive to Cd2+.

The obvious drawback of the MeTROSY approach is that it is not ap

The obvious drawback of the MeTROSY approach is that it is not applicable to 14 out of 20

amino acids. While typically Ganetespib cell line only methyl groups in Ile, Leu, Val are observed [4], specific isotope labeling strategies have also been developed for Met, Ala (reviewed in [5]) and Thr [6]. The limited sequence coverage of MeTROSY can be alleviated to some extent by site-specific introduction of 13CH3 groups at desired positions, for example by site-directed mutagenesis, if the structure allows for it. Such MeTROSY-based methionine scanning of solvent exposed residues has recently been proposed to map binding interfaces [7]. Alternatively, a single methyl probe may be introduced by di-sulfide bond formation with a 13CH3–S group from methylmethanethiosulfonate resulting in the methione-mimic S-methylthiocysteine [8]. Both backbone amide-based TROSY and MeTROSY experiments have proven to allow studies of protein structure, dynamics and interaction in systems as large as 1 MDa (Table 1). In addition, other approaches such 13C direct detection

[9] and [10] or stereo-selective amino acid labeling [11] and [12] can help to study large molecular systems. Yet, despite these advances, low molecular tumbling rates inherently limit the applicability of solution-state NMR. In contrast, the resonance line width in magic-angle spinning (MAS) solid-state NMR (ssNMR) is independent of the protein molecular weight. Recently, Reif find more and co-workers Dimethyl sulfoxide as well as Bertini et al. have shown that also soluble protein complexes can be investigated by ssNMR in an approach referred to as FROSTY

[13] or sedNMR (sedimented NMR) [14]. Strong centrifugal forces during MAS lead to reversible protein sedimentation at the inner wall of the MAS rotor for protein complexes above 100 kDa, effectively creating a solid. Complexes can also be sedimented into the rotor by conventional ultracentrifugation using a dedicated filling-device [15] and [16]. Sedimented ssNMR is thus a promising method to overcome the size barrier in solution NMR. Various types of NMR experiments can provide low-resolution structural information even for large systems. Assuming that the stoichiometry and composition of the macromolecular complex under study are known, these can provide useful insights into binding sites, distances between specific pairs or groups of atoms, and relative orientation of subunits. The most frequently used data and their information content are summarized in Table 2. The workhorse of NMR for interaction studies is chemical shift perturbations (CSP) mapping, a simple comparison of peak positions in spectra before and after adding a (unlabeled) binding partner. Ligand binding induces changes in the chemical environment of the observed protein, which can conveniently be monitored by NMR (Fig. 1).

This work was supported by funding and fellowships from the Brazi

This work was supported by funding and fellowships from the Brazilian Agencies: Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Ministério da Educação, Brazil (CAPES-MEC) – Edital Toxinologia (Processo: 23038.006277/2011-85) and Conselho Nacional de Desenvolvimento Científico e Tecnológico, find more Ministério da Ciência e Tecnologia, Brazil (CNPq-MCT). “
“Bothrops snake venoms are mainly composed of enzymes such as phospholipases A2 (PLA2s), metalloproteases (SVMPs), and l-amino acid oxidases (LAAOs), that can induce

a wide range of toxic effects, such as myotoxicity, hemorrhage, blood coagulation, neurotoxicity, cytotoxicity, edema, cellular apoptosis, genotoxicity, as well as others of medical interest, such as antimicrobial, antiparasitic, antifungal and antiviral activities ( Iwanaga and Suzuki, 1979; Kang et al., 2011; Vonk et al., 2011; Marcussi et al., 2011; Soares, 2012). PLA2s from Bothrops Omipalisib molecular weight venoms are the main components responsible for cellular damage through the hydrolysis of membrane phospholipids. Those PLA2s known as myotoxins belong to the IIA group of PLA2s and may be classified into two subgroups:

(i) Asp49 myotoxins (for example, Bothrops jararacussu BthTX-II), with low to moderate enzymatic activity, and (ii) Lys49 myotoxins (as B. jararacussu BthTX-I), which do not show any hydrolytic activity on synthetic substrates ( Soares et al., 2004; Lomonte and Gutiérrez, 2011; Lomonte and Rangel, 2012). BjussuMP-II is a P–I class metalloprotease isolated from B. jararacussu venom with molecular mass of 24 kDa, which showed fibrinogenolytic

and caseinolytic activities, without presenting hemorrhagic or myotoxic effects ( Marcussi et al., 2007). An LAAO from Bothrops atrox, named BatxLAAO, is a single-chained glycoprotein with a molecular mass of 67 kDa, pI 4.4 and 12% sugar content. It presents moderate edematogenic activity and does not induce hemorrhage. Moreover, it presents cytotoxic activity on different tumor cells, but not on normal cells (mononuclear cells from peripheral blood) ( Alves et al., 2008). Molecules isolated from venoms show a significant medical-scientific relevance due to their action on cells, and could be used in structural studies in order to improve the understanding of several cell processes and mechanisms. These molecules can also be used as models 3-oxoacyl-(acyl-carrier-protein) reductase in to the development of new therapeutic agents that could be used in new therapies for snakebite accidents and pathologies, such as cancer, thrombosis and hypertension (Koh et al., 2006; Lomonte et al., 2010; King, 2011; Koh and Kini, 2012; Soares, 2012). Considering several papers that describe the therapeutic potential of animal venom toxins for various diseases, the evaluation of their toxicity against human cells is necessary to gauge the difference between non effective, therapeutic or toxic doses for these molecules in order to adjust administration protocols.

Irrespective of the spray generation method, it is advisable to m

Irrespective of the spray generation method, it is advisable to measure particle size distribution and other aerosol characteristics and their time-dependent change, including agglomeration, sedimentation, and ageing effects in order to make a thorough safety assessment. Common methods of particle size measurement include, e.g., laser diffraction, use of the cascade impactor and time of flight spectroscopy, but droplets can change

Selleck BYL719 due to ageing processes during the flight phase so care must be taken when analysing measured data. Droplet diameter may decrease by evaporation of volatile constituents. Droplets may disperse after collision with solid surfaces, they may aggregate, and deposit on solid surfaces. Therefore, any spray pattern is subject to constant changes, and the interpretation and application of any such analytical data

to the safety assessment must be carried out keeping in mind the limitations of accuracy and applicability of such data. Furthermore, the setting of product- and method-specific parameters in the establishment of such analytical methods requires great experience and well trained personnel. A detailed overview on particle size measurement methods is given in the guidance document of the European Aerosol Association FEA (FEA European Aerosol Federation, 2009). selleck chemicals To prepare a proper safety assessment for spray products the best knowledge on the inhalation exposure under intended use conditions should be available or estimated. Real time measurements of specific product exposure represent the gold standard, but need complex and extensive study designs. More simple mathematical approaches taking into account worst case defaults can be used as a first step in a tiered approach for exposure assessment. Easily, the concentration of any ingredient in the ambient air can be calculated on the basis of the worst-case estimation Chlormezanone of the applied amount, duration of application as well as the distribution volume, e.g., the volume of a standard

bath room. By using conservative defaults (see below) the calculation of the exposure will overestimate the real situation of human exposure. A clear advantage of this approach is that a safety assessment may be rapidly performed and is independent of extensive measurements. In those cases where a risk assessment on the basis of such an initial conservative procedure does not yield a sufficient safety margin, a refined exposure assessment needs to be conducted. Relevant data that reflect actual application situations may be generated by measuring aerosol concentration and particle size in a model environment (for example a standard bathroom). Reality-based mathematical models (e.g., ConsExpo 4.1 (Bremmer et al., 2006a), BG-Spray (Eickmann, 2007a)) can also be used to quantify aerosol concentrations over time.