The mechanisms responsible are just as varied and include hydroph

The mechanisms responsible are just as varied and include hydrophobic, electrostatic animal study and van der Waals interactions as well as structural changes in the molecule, which may result in entropy or enthalpy changes, though hydrophobic ones are usually considered to be the most important.34 Adsorption is often considered to be a reversibel process, but this is only partially true and depends on the free energy of the adsorption: the higher this is, the less reversible the process will be. During the initial minutes the interaction between protein and surface is fast and indeed reversible, but then the surface induces conformational changes in the protein that increase the interaction and can lead to complete protein denaturation after unlimited adsorption time.

35 These conformational changes contribute to the free energy and thus reduce desorption, but as these changes are comparatively slow the desorption rate can be described as a function of the contact time. Molecules with very stable conformations can be expected to have only negligible changes with little contribution to the free energy, thus forming no strong adsorptive interactions. An exception are large, fibrillar proteins: due to their high surface to volume ratio they have a much higher number of potential binding sites than globular proteins of a comparable size, and they can interact with the surface via several segments. Although the adsorption free energy of each segment may be small as no structural changes take place to contribute, engagement of many segments will increase the total adsorption free energy until the molecule does not readily desorb anymore.

36 In this case there is no time dependency and adsorption is irreversible even after short times. For this reason collagen fibrils can be immobilized using this method with concentrations between 40 to 60 ��g/cm2, and are still stable against competitive adsorption of serum proteins.37 Solvents of a higher ionic strength tend to reduce immobilization by about 20%, which indicates the importance of electrostatic interactions. The effect is somewhat larger on collagen type III, but generally there are no significant differences to collagen I, and this may only be caused by the higher surface area resulting from the finer fibrils. Heterotypic fibrils again take intermediate positions.

12 Including non-collagenous components usually had no influence on the adsorbed amount, excepting very thin fibrils as seen for high decorin concentrations.3 The adsorption of all types of collagen-based aECM is thus determined by Drug_discovery the collagen part. Characterizing aECM Biochemical characteristics This includes the stability of the matrices against desorption, the release of individual components (especially for multi-component aECM that depend on physiological, non-covalent interactions), as well as the bioavailability and functionality of the components (a large issue for crosslinked matrices).

carvi extract Cmax of rifampicin increased from 4 57 ?? 0 19 to 5

carvi extract Cmax of rifampicin increased from 4.57 ?? 0.19 to 5.95 ?? 0.19 (32.22%) (P = 0.000) and AUC (0-24) from 40.11 ?? www.selleckchem.com/products/Tubacin.html 1.69 to 53.01 ?? 1.88 (32.16%) (P = 0.000), respectively. Whereas volume of distribution (Vd) decreased from 43.94 to 31.03 and clearance (Cl) from 8.45 to 6.14. Tmax remained constant at 4 h. Half-life (t?) was not altered significantly. The pharmacokinetic parameters of isoniazid showed an increase in Cmax from 2.66 ?? 0.16 to 3.62 ?? 0.16 (36.01%) (P = 0.000), AUC (0-24) from 17.72 ?? 0.78 to 22.87 ?? 0.94 (29.06%) (P = 0.000). Volume of distribution (Vd) decreased from 35.71 to 27.54 and clearance (Cl) from 13.75 to 9.62. Tmax was constant at 3 h. And half-life (t?) was not altered significantly. Cmax of pyrazinamide showed an increase from 18.81 ?? 0.79 to 25.

06 ?? 1.14 (33.22%) (P = 0.000), AUC(0 ? 24) increased from 107.65 ?? 4.42 to 137.71 ?? 5.92 (27.92%) (P = 0.000). Volume of distribution (Vd) decreased from 28.12 to 19.39 and clearance (Cl) from 6.719 to 5.17. Tmax was 3 hrs with both test formulations. Half-life (t?) was not significantly different [Table 2]. Table 2 Pharmacokinetic parameters of rifampicin, isoniazid, and pyrazinamide with TF-A and TF-B DISCUSSION Tuberculosis is a complex socioeconomic disease that apart from its alarming death statistics in developing countries is also a cause of concern for industrialized nations. Its treatment poses many difficulties in the form of poor and variable bioavailability of antitubercular drugs. Of many approaches applied for increasing bioavailability of these drugs, one is use of herbal bioenhancers.

Earlier reports in rats indicate bioenhancing potential of C. carvi when it was administered along with rifampicin.[10] A recent report has also shown its bioenhancing action on rifampicin, isoniazid, and pyrazinamide in rats.[11] The current study has indicated bioenhancing potential of C. carvi along with ATT therapy for the first time in humans. Thereby there exists the possibility of ameliorating the dose-related toxicity of ATT by allowing Entinostat reformulation of dose reduction. C. carvi has been used since ages for many ailments in different parts of the world. It is a prized culinary herb, which is extensively used across different cultures. This herb has been mentioned in Ayurveda and other Indian systems of medicine prescriptions for a variety of ailments.

It has been used as a carminative, stomachic, aromatic, and diuretic.[14] There has been no study till date using C. carvi as bioenhancer along with antitubercular drugs in humans. The present study is the first of its kind to determine in humans the bioenhancing potential selleck chemical of C. carvi along with antitubercular drugs. In our study, the various pharmacokinetic parameters were comprehensively studied. The results show that addition of C. carvi extract led to increase in plasma levels of rifampicin, which peaked at 4 h.

The organization of the Dominantly Inherited Alzheimer Network [5

The organization of the Dominantly Inherited Alzheimer Network [5] has been a major accomplishment in creating the logistic basis of such clinical trials, although owing to the small sample size, it is not likely that else all drugs can be tested in this specific population. On clinical grounds, EOAD and LOAD are distinguished on the basis of age of onset (AOO) alone. Several studies attempted to delineate the clinical, neuropsycho-logical, imaging, pathological, and biomarker differences between EOAD and LOAD based on the 65-year arbitrary cutoff proposed by Amaducci and colleagues [1] in 1986. The age of disease onset of patients with AD ranged from 50 to 99 in most studies but included subjects with AOO as low as 41 years in a few.

As AOO is an estimate, the attempt to dichotomize the AOO distribution introduces both misclassification of subjects around the cutoff and noise into the datasets. Furthermore, diverse onset ages within genetically defined families demonstrated that, even with the same upstream trigger, AOO can vary, suggesting that other genetic and environmental factors contribute to the AOO phenotype [6]. In addition, in vivo diagnosis of AD is estimated at 95% accuracy, and therefore introduces noise due to some misclassification bias [7]. After consideration of these limitations, there have been few replicable clinical differences between the EOAD and LOAD groups. Differences in the neuropsychological profiles are controversial and inconsistent between studies.

While there is a consensus that LOAD appears to have a more predominant impairment of memory (with verbal memory affected more severely than nonverbal memory in general [8]), it remains unclear whether language, visuospatial abilities, and praxis are more affected or preserved in EOAD compared with LOAD [9]. The literature suggested that AV-951 language is more affected in EOAD with preservation of visuospatial function [10,11], whereas more recently, praxis and visuospatial function appeared to be more affected when compared with LOAD [12]. Most research data support the hypothesis that there is greater involvement of the frontal-parietal structures in EOAD and more predominant deficits in temporal lobe function with a propensity for the left hemisphere in LOAD [10,13,14] Studies investigating the rate of disease progression by measuring cognitive and functional abilities over time yielded variable results.

Some reports demonstrated that EOAD shows a more rapid progression [15-17], and others found that AOO is not a major predictor of the rate of progression [18,19]. Most voxel-based volumetric magnetic resonance imaging studies found that, in LOAD, hippocampal atrophy is prominent [20] whereas the pattern in EOAD is more variable. In EOAD, instances of atrophy of the temporal-parietal [21], then parietal-occipital [20], temporal and posterior cingulate [22], and precuneus [23] areas have been reported.

Taking this into consideration, children have been submitted to p

Taking this into consideration, children have been submitted to preventive programs based on regular plaque control by professional prophylaxis, which aims to compensate for poor toothbrushing.11�C16 When regularly performed, professional prophylaxis may significantly reduce the progression of dental caries.11�C15 One method for performing this procedure is the use of sodium bicarbonate. selleck chem inhibitor Investigations comparing the effectiveness of prophylaxis using sodium bicarbonate with that performed using rubber cup and pumice reveal that sodium bicarbonate removes dental plaque more effectively, especially in pit and fissure regions.16,17 Tooth wear could be a possible adverse effect of the regular use of sodium bicarbonate.

Thus, several studies have been conducted to quantify the amount of tooth structure removed in each session of professional prophylaxis using sodium bicarbonate.18�C20 In general, authors agree that sodium bicarbonate has a slight effect on intact enamel.18�C20 However, these studies evaluated the dental surface immediately after the procedure, while doubts still remain concerning the protective capacity of the oral environment due to the presence of saliva and/or fluoride. Oral fluids may offer some protection, even when considering the loss of tooth structure by abrasion caused by the mechanical action of sodium bicarbonate under water pressure. Saliva is rich in minerals and proteins, it is supersaturated with calcium and phosphate ions, and it lubricates the teeth.21 Thus, saliva acts against demineralization and may be able to recover the slight mineral loss of enamel caused by prophylaxis using sodium bicarbonate.

Furthermore, fluoride can increase the rate of re-mineralization due to its mechanism of action.8,22 However, it is not known whether fluoride may influence the redeposition of minerals in case of abrasion of enamel surfaces. Considering such aspects, this in situ study aimed to evaluate the effect of saliva, whether associated or not with fluoride, on enamel that had previously been subjected to prophylaxis using sodium bicarbonate. MATERIAL AND METHODS Experimental design This in situ study involved a crossover, blind design performed in two phases of 4 hours,20 with a wash-out period of 7 days. The groups under study were: G1��treatment with sodium bicarbonate jet in vitro and saliva exposure for 4h in situ, and G2��treatment with sodium bicarbonate jet in vitro, 0.

2% NaF rinse during the first minute and saliva exposure for 4h in situ. Each phase corresponded to one group: G1 or G2. Ten healthy adult volunteers living in the same fluoridated area (0.7 ppm) with a mean age of 28 years (range Brefeldin_A 23�C35 years) and normal salivary flow rate took part in this study after signing an informed, written consent, approved by the IRB of Bauru Dental School, University of S?o Paulo. They wore acrylic palatal appliances, each containing two dental enamel blocks (Figure 1). Figure 1.

According to the literature, nanoparticle ��-potentials above 30

According to the literature, nanoparticle ��-potentials above 30 mV or below -30 mV are considered stable.20 As shown in Table 1, all nanoparticles, are near -30 mV indicating that they selleck chem are stable. Effects of lyophilization on core + shell nanoparticles Lyophilization is an effective way to prevent the release of therapeutics loaded into PLGA nanoparticles during long-term storage.10,11 However, if not performed correctly, lyophilization can result in aggregation of the PLGA nanoparticles that prevents resolubilization of the clumped nanoparticles (Fig. 2).10,11 We used TEM imaging to visually confirm that well-defined spherical PLGA and PLGA core + pNIPAM shell nanoparticles were successfully fabricated (Fig. 2). However, as also observed by others,10,11 TEM imaging showed that lyophilization caused the PLGA nanoparticles to form aggregates (Fig.

2). This aggregation resulted in an inability to measure diameter and ��-potential of post-lyophilized PLGA nanoparticles. In contrast, encapsulation of PLGA nanoparticles with pNIPAM shells prevented aggregation of the PLGA nanoparticles following lyophilization, further confirming that the pNIPAM shell fully encapsulated the PLGA core. Additionally, we found that lyophilization of the core + shell nanoparticles does not affect their size or ��-potential at 25��C or 37��C (Table 1). Figure 2. Transmission electron microscope images of the various nanoparticles both pre- and post-lyophilization. Scale bars = 250 nm.

Responses of core + shell nanoparticles to dynamic environmental stimuli To further assess the response of our core + shell nanoparticles to temperature-based environmental stimuli, we used dynamic light scattering to measure the diameter of our core + shell nanoparticles as they were exposed to a dynamic range of temperatures from 20��C to 50��C to 20��C. We found that the core + shell nanoparticles readily respond within this temperature range with all core + shell nanoparticle types decreasing in diameter as the temperature was raised above their LCST (Fig. 3). This response was reversible, as the nanoparticles returned to their original diameter when the temperature was lowered back below their LCST. Additionally, the LCST of the pNIPAM shell was tuned by modifying the amount of acrylic acid that was incorporated as a co-monomer. As more acrylic acid was incorporated, the LCST of pNIPAM increased (Fig.

3). The core + shell nanoparticles with 0 mol% acrylic acid exhibited an LCST at ~31�C32��C, while the 1 mol% acrylic acid had an LCST at ~33�C34��C, and the core + shell nanoparticles with 5 mol% acrylic acid had an LCST at ~35��C (Fig. 3). This trend has previously been established in the literature.19,21 In the future, these core + shell nanoparticles Carfilzomib could be engineered to respond to different environmentally based stimuli in addition to temperature by changing the co-monomer composition of the pNIPAM.14 Figure 3.

001 -respectively for pretest and post-test) Strength in tethere

001 -respectively for pretest and post-test). Strength in tethered swimming A significant improvement find protocol of tethered swimming force for the experimental group (9.64%, p<0.02) was found, whereas the increase was not statistically significant from pretest to post-test conditions (2.86%, p>0.05) in the control group. In addition, tethered swimming force was similar in the control and experimental groups at pretest and post-test evaluations (p>0.05). Moreover, the experimental group presented higher values of TS compared with the control group (35.50%, p<0.001) after six weeks of power training. However, the experimental group presented higher values of TS compared with the control group (27.10%, p<0.002) from the start of the research.

Discussion This study aimed to investigate the effects of a six week combined dry-land strength and aerobic swimming training on upper body strength, tethered swimming force and swimming performance in youth competitive swimmers. It is considered that traditional dry-land strength training or combined swimming and strength training do not appear to enhance swimming performance in untrained individuals or competitive swimmers (Tanaka and Swensen, 1998). It was previously observed that although combined training increases upper body strength, it does not result in faster sprint times compared with swimming-only training (Tanaka et al., 1993). Additionally, Bulgakova et al. (1990) reported that water strength training was more effective than dry-land strength exercises. Additionally, Bulgakova et al.

(1990) reported that strength training in water is more effective than dry-land strength training. Many authors indicate that in youth swimmers technical training is more important than strength training (Kjendlie et al., 2004, Aspenes et al. 2009; Barbosa et al., 2010; Garrido et al., 2010). According to our data, it is not clear that strength training allowed the improvement in swimming performance in youth swimmers although a tendency to improve performance due to both types of training was noticed. It is uncertain whether dry-land strength training leads to improved sprint performance while swimming. Tanaka et al. (1993) explained lack of significant transfer between dry-land strength training and swim performance by the ambiguity of swimming and dry-land training condition.

Different factors determine to what extent training progress in one situation leads to improved performance in the other. Previous studies showed that training effects are angle and velocity-specific. This suggests that effects of dry-land strength training are transferred to the swimming if during strength training people move just as fast or even faster than during swimming in water (Toussaint et al., 1988). Moreover, not only the movement velocity during strength training should Brefeldin_A correspond to that during swimming, but also the relationship between joint angle and strength must be similar to that in water condition.

1) Samples with large fibers absorbed TCH less efficiently than

1). Samples with large fibers absorbed TCH less efficiently than those with small fibers because they had less specific surface area to absorb TCH. As a consequence, samples D, Wortmannin cost P and Ca absorbed and released less TCH than the control (p < 0.05). Samples D, P and Ca absorbed and released similar amounts of TCH during the course of the test (p > 0.05). It seemed that the TCH release percentages of the samples corresponded with their swelling ratios. Samples P and Ca had the highest and lowest swelling ratios of all and they also had the highest and lowest parentages of TCH release, respectively, at 6 h. Samples with more loose fibrous structures swelled up faster (section 2.3) and as a consequence released the absorbed TCH more quickly. Figure 6. The cumulative TCH release of different samples over 6 h in PBS.

Data are presented as the mean �� SD (n = 6). The total amount of TCH released within 48 h was the amount of TCH loaded on the sample. The percentages of TCH released … Alginate itself and what it might release did not inhibit the growth of E. coli (Fig. 7A). Only the TCH released from the samples did inhibit the growth of E. coli and form an inhibition zone. Sample A had the largest inhibition zone of all of the samples (p < 0.05) (Fig. 7B), most likely due to the highest amount of TCH it released. Sample P had a larger inhibition zone than the control and Ca had a smaller one (both p < 0.05). The inhibition zone of sample D was similar to that of the control (p > 0.05). There did not seem to be a strong correlation between the amount of TCH loaded, their release pattern, and the size of inhibition zone.

However, the most important issue in wound care is not the delivery mechanism but rather finding medications that can be topically absorbed, which provides desirable therapeutic effects within wounds.4 Figure 7. (A) Representative pictures of the antibacterial effect of samples releasing tetracycline HCl (TCH). (B) The bacterial inhibition zone of the samples loaded with (TCH). Data are presented as the mean �� SD (n = 8). *Indicates … Materials and Methods Sample preparation Alginic acid monosodium salt was extracted from brown seaweed with a ratio of mannuronic acid to guluronic acid (M/G ratio) of 1.56 and a molecular weight of 100,000 Da (Sigma). The viscosity of the 2% alginate aqueous solution at 25��C was 150 cP (ARES Rheometer, Rheometric Scientific).

Alginic acid monosodium salt was dissolved in deionized water, and the solution was loaded into a plastic syringe, which was immobilized onto a robotic arm and kept at room temperature. Air pressure was applied to the syringe through a pneumatic regulator (8000D, Ganbow) to expel the alginate solution through a needle into a container filled with calcium chloride solution in which the gelation process Cilengitide of the alginate fibers occurred. For the tensile and water vapor transmission rate tests, 35 mL of alginate solution was extruded into a plastic container (5.5 cm �� 3.

4 2 Screening from a Vascular Point of View Both CT angiography

4.2. Screening from a Vascular Point of View Both CT angiography selleck chemicals llc selleck kinase inhibitor and conventional angiography were used to evaluate vascular integrity and anatomy within the residual limb. Patients screened in 2008 typically underwent CT angiography while the later patients were screened using conventional angiography. This change was multifactorial, influenced in part by the increasing sensitivity to radiation exposure and awareness of renal drug sensitivity. In addition, technological advances facilitated the transition as the two modalities became fairly comparable in quality, but with the advantage that conventional imaging could be acquired using less contrast when performed by an experienced interventionalist [8�C10].

At our institution, vascular mapping whether by CT or conventional angiography focused on identifying vessels adequate to serve as the vascular pedicle for the transplant. Features that defined acceptability were those proven in other transplant populations to decrease the degree of turbulence and thus complication, such as large vessel caliber, relative lack of branching, and maximum vessel length [8, 11�C13]. Thus, a preference was placed on using the radial and ulnar arteries, rather than collaterals, and attention was directed to the length of the preserved vessels and their approximation to the distal-most aspect of the residual limb. 4.3.

Musculoskeletal Postsurgical Surveillance Since extremity composite tissue transplantation entails the transfer of multiple tissue types which each heal and reject independently, radiological surveillance attempted to monitor for signs of both processes [2, 3].

Postsurgical radiologic imaging focused on documenting transplant healing and the exclusion of postsurgical complication. These concerns were largely answerable by conventional radiography using serial radiographs, with CT and MRI being secondary modalities to further evaluate any irregularity detected on the initial radiograph or on physical examination. The Anacetrapib structural concerns dictating imaging within the postsurgical period were akin to conventional orthopedic procedures with attention given to osseous alignment, progressive signs of healing, and surveillance for hardware failure.

It can be argued whether the radiologist should comment on the subjective bone density observed on follow-up radiographic studies given these patients’ ongoing immunosuppressive therapy. Although little exists in the literature concerning the long-term effects of Tacrolimus (FK506) on bone Drug_discovery healing in humans, FK506 has been shown to decrease trabecular bone density in rat models secondary to increased osseous resorption [14].

2 6 Statistics Statistical analysis was performed using the S

.. 2.6. Statistics Statistical analysis was performed using the SigmaStat11?2 program (Aspire Software International, Leesburg, VA, USA) by the Kruskal-Wallis one way analysis of variance on ranks and by Holm-Sidak for all pairwise multiple comparison procedures. Data were expressed as the median, range, and mean �� s.d./s.e.m. The P selleck inhibitor values smaller than or equal to 0?05 were considered as significant. 3. Results 3.1. Demographic and Clinical Data Demographic, clinical, and laboratory characteristics of the patients are summarized in Table 1. Initial immunosuppressive regimen included cyclosporine/azathioprine/prednisone in 3 (21%) ELTGF patients; the remaining 11 (79%) ELTGF patients received azathioprine/prednisone only since the initial post-KT course, with current mean doses of 82.5 �� 23.

7mg/day and 4.8 �� 0.8mg/day, respectively. It is worth mentioning that 2 ELTGF patients withdrew immunosuppression motu proprio at 1 and 3 years posttransplant and have remained stable without it for 25 and 16 Inhibitors,Modulators,Libraries years, Inhibitors,Modulators,Libraries respectively (operational tolerant). In addition, immunosuppression was withdrawn in another ELTGF patient, 13 years after transplantation during hospitalization for fever, headache, and brain MRI lesions suggestive of a posttransplant lymphoproliferative disorder. Patient has remained off immunosuppression since then and is currently in her Inhibitors,Modulators,Libraries 14th year posttransplant. Table 1 Demographic and clinical data of kidney transplant recipients. In 6 (67%) patients from CGD group, triple drug immunosuppression scheme consisted of CNI (tacrolimus, mean blood level 6.0 �� 2.

9ng/mL, cyclosporine, mean blood level 71.2 �� 27.2ng/mL), mycophenolate mofetil (mean daily dose 1.0g), and prednisone (mean daily dose 5.0mg). The remaining 3 (33%) patients received sirolimus (mean blood level 8.3 �� 3.7ng/mL), mycophenolate mofetil (mean daily dose 1.0g), and prednisone (mean daily dose 5.0mg). 3.2. Biopsies Inhibitors,Modulators,Libraries Three graft biopsies from 3 different ELTGF patients were performed at 6, 16, and 21 years posttransplant. Unspecific findings such as mild CNI toxicity, Inhibitors,Modulators,Libraries mild interstitial fibrosis, and interstitial fibrosis and tubular atrophy of less than 15% were observed, respectively. Twenty four biopsies from 9CGD patients were performed during posttransplant followup. A history of acute cellular rejection Banff IB and acute humoral rejection grade I was found in biopsies from 2 different patients.

These latter patients received treatment with methylprednisolone boluses (n = 1), plasmapheresis, IVIg, Drug_discovery methylprednisolone boluses, and bortezomib (n = 1). Overall, evidence of CNI and interstitial fibrosis and tubular atrophy was found in 57%, and data suggestive of chronic rejection was observed in 78% of patients from the CGD group. It is important to highlight that currently, eGFR is doubled in ELTGF versus CGD group (Table 1). Also, the immunosuppressive regimen is more intensive in patients with CGD. 3.3.

Pyrene is present in almost all PAH mixture in relatively high co

Pyrene is present in almost all PAH mixture in relatively high concentrations and there is a good correlation between pyrene and other components in PAH mixture [2]. www.selleckchem.com/products/MG132.html 1-OHP (1-hydroxypyrene), a major metabolite of pyrene, has been widely used as an indicator of internal exposure to PAH [3,4]. The main source of PAH intake is food, on the one hand as a result of airborne PAH precipitating onto cereals, fruit and vegetables, and on the other hand as a result of PAH generated during the preparation of food. For example, smoked food and food grilled on open flames display substantial levels of PAH content [5]. A very important source of PAH exposure among the general population is tobacco smoke [6]. Smokers�� intake of pyrene in cigarette smoke is of the same order of magnitude as intake from average food consumption [7].

It has been shown that domestic wood burning, residential charcoal burning stoves and barbecue charcoal combustion turn out to be important sources of pollutant exposure to humans [8,9]. In DRC (Democratic Republic of Congo), only 5% of the population has access to electricity. As a result, wood energy production accounts for 85% of total energy consumption and fuel wood and charcoal are by far the most heavily consumed energy sources in DRC [10,11], used primarily for household heating and cooking. In this study, we provide the first data for biomonitoring PAH in a representative sample of the Kinshasa population. The values were compared to those reported by the reference values from American [12] or German databases [13].

Methods Study design In the absence of reliable population registers and in view of the practical difficulties of conducting a truly random sampling in the population of Kinshasa, we applied a two-stage systematic sampling approach [14]. In the first stage, the 22 administrative entities of Kinshasa were listed in alphabetical order and 11 out of them were selected as follows: a first entity was drawn randomly from the list and every other subsequent entity was then included, thus ensuring a comprehensive coverage of the entire urban area of Kinshasa. In the second stage, we aimed to recruit about 25 healthy male and female subjects between 6 and 70 years from each of the 11 entities. In a mobilization campaign (mainly by word of mouth), healthy subjects were invited to come to the local health center to provide a urine sample.

After exclusion of 13 individuals AV-951 because of possible direct occupational exposure to PAH (asphalt application, waste incineration, aluminum smelting), 220 individuals provided a urine sample and were included in the present study (80% of the target number was reached). Informed consent was obtained from each subject and information on age, gender, place of residence and smoking habits were recorded. With the same methods of mobilization campaign, fifty additional subjects living in the sub-rural area of Kinshasa were also included.