Usporedba dinamičke analize para iznad otopine i mikroekstrakcije analita na čvrstoj fazi za plinskokromatografsko određivanje BTEX-a u urinu

The aim of this study was to compare two extraction procedures: dynamic headspace-purge and trap (PT) and headspace solid-phase microextraction (HS-SPME) for gas chromatographic determination of benzene, toluene, ethylbenzene, and isomeric xylenes (BTEX) in urine with photoionization (PID) and mass spectrometric (MS) detection, respectively. Both methods showed linearity in the range of interest [(50-2000) ng L-1], good accuracy (80% to 100 %), and repeatability (RSD≤11 %). Detection limits were in the low ng L-1 level for both methods, although slightly greater sensitivity was found for the PT method. In comparison with PT, HS-SPME was simpler and required less time for analysis. Although the analytical features of both examined methods are appropriate for biomonitoring of environmental exposure to BTEX, only the HS-SPME-GC-MS method is recommended for routine analysis of BTEX in urine. The method was applied for the quantitative analysis of BTEX in urine samples collected from non-smokers (n=10) and smokers (n=10).Cilj ovog rada bio je usporediti dva postupka ekstrakcije za plinskokromatografsko određivanje benzena, toluena, etilbenzena i izomera ksilena u urinu. Uspoređene su dinamička analiza para iznad otopine (tzv. purge and trap) uz fotoionizacijski detektor i mikroekstrakcija analita na čvrstoj fazi uz detektor spektrometar masa. Rezultati upućuju na linearnost odziva detektora u ispitivanome koncentracijskom području [(50- 2000) ng L-1], zadovoljavajuću točnost (80 %-100 %) i ponovljivost (RSD ≤11 %). Postignute su niske granice detekcije za obje metode. Mikroekstrakcija analita na čvrstoj fazi uz detektor spektrometar masa pokazala se jednostavnijom i bržom za izvođenje pa se preporučuje za rutinsko određivanje BTEX-a u urinu. Metoda je primijenjena za analizu tih spojeva u uzorcima urina nepušača (n=10) i pušača (n=10)

Event-Related Potentials in Medical Workers with Long-Term Exposure to Xylene

The effects of chronic exposure to xylene on cognitive ability were studied in a group of 35 medical workers occupationally exposed to low-level concentrations of xylene for at least five years by using event-related potentials (ERPs), and compared with a control group of 21 subjects. The exposure to xylene was confirmed through determination of m-methylhippuric acid, a reliable biological indicator of xylene exposure, in pre- and post-shift urine. A dose-effect relationship between log m-methylhippuric acid and ERP log latency (p = 0.032), and the ERP amplitude (p = 0.047) was statistically significant. The group of medical workers showed significantly longer ERP log latency (p < 0.001) than did the control group with respect to factors of exposure to smoking, education and age as covariates. For the ERP amplitude the difference was found not to be significant (p = 0.263), probably due to high between subject variability. The cognitive impairment may occur in workers chronically exposed to xylene

Dermanyssus gallinae in layer farms in Kosovo: a high risk for salmonella prevalence

Background The poultry red mite (PRM), Dermanyssus gallinae (D.g.) is a serious ectoparasitic pest of poultry and potential pathogen vector. The prevalence of D. g. and the prevalence of Salmonella spp. within mites on infested laying poultry farms were investigated in Kosovo. Findings In total, 14 populated layer farms located in the Southern Kosovo were assessed for D. g. presence. Another two farms in this region were investigated 6 months after depopulation. Investigated flocks were all maintained in cages, a common housing system in Kosovo. A total of eight farms were found to be infested with D. g. (50%) at varying levels, including the two depopulated farms. The detection of Salmonella spp. from D. g. was carried out using PCR. Out of the eight layer farms infested with D. g., Salmonella spp. was present in mites on three farms (37.5%). Conclusions This study confirms the high prevalence of D. g. in layer flocks in Kosovo and demonstrates the link between this mite and the presence of Salmonella spp. on infested farms

Global challenges with scale-up of the integrated management of childhood illness strategy: results of a multi-country survey

<p>Abstract</p> <p>Background</p> <p>The Integrated Management of Childhood Illness Strategy (IMCI), developed by WHO/UNICEF, aims to contribute to reducing childhood morbidity and mortality (MDG4) in resource-limited settings. Since 1996 more than 100 countries have adopted IMCI. IMCI case management training (ICMT) is one of three IMCI components and training is usually residential over 11 consecutive days. Follow-up after ICMT is an essential part of training. We describe the barriers to rapid acceleration of ICMT and review country perspectives on how to address these barriers.</p> <p>Methods</p> <p>A multi-country exploratory cross-sectional questionnaire survey of in-service ICMT approaches, using quantitative and qualitative methods, was conducted in 2006-7: 27 countries were purposively selected from all six WHO regions. Data for this paper are from three questionnaires (QA, QB and QC), distributed to selected national focal IMCI persons/programme officers, course directors/facilitators and IMCI trainees respectively. QC only gathered data on experiences with IMCI follow-up.</p> <p>Results</p> <p>33 QA, 163 QB and 272 QC were received. The commonest challenges to ICMT scale-up relate to funding (high cost and long duration of the residential ICMT), poor literacy of health workers, differing opinions about the role of IMCI in improving child health, lack of political support, frequent changes in staff or rules at Ministries of Health and lack of skilled facilitators. Countries addressed these challenges in several ways including increased advocacy, developing strategic linkages with other priorities, intensifying pre-service training, re-distribution of funds and shortening course duration. The commonest challenges to <it>follow-up </it>after ICMT were lack of funding (93.1% of respondents), inadequate funds for travelling or planning (75.9% and 44.8% respectively), lack of gas for travelling (41.4%), inadequately trained or few supervisors (41.4%) and inadequate job aids for follow-up (27.6%). Countries addressed these by piggy backing IMCI follow-up with routine supervisory visits.</p> <p>Conclusions</p> <p>Financial challenges to ICMT scale-up and follow-up after training are common. As IMCI is accepted globally as one of the key strategies to meet MDG4 several steps need to be taken to facilitate rapid acceleration of ICMT, including reviewing core competencies followed by competency-driven shortened training duration or 'on the job' training, 'distance learning' or training using mobile phones. Linkages with other 'better-funded' programmes e.g. HIV or malaria need to be improved. Routine Primary Health Care (PHC) supervision needs to include follow-up after ICMT.</p

Morphology and density of post-CME current sheets

Eruption of a coronal mass ejection (CME) drags and "opens" the coronal magnetic field, presumably leading to the formation of a large-scale current sheet and the field relaxation by magnetic reconnection. We analyze physical characteristics of ray-like coronal features formed in the aftermath of CMEs, to check if the interpretation of this phenomenon in terms of reconnecting current sheet is consistent with the observations. The study is focused on measurements of the ray width, density excess, and coronal velocity field as a function of the radial distance. The morphology of rays indicates that they occur as a consequence of Petschek-like reconnection in the large scale current sheet formed in the wake of CME. The hypothesis is supported by the flow pattern, often showing outflows along the ray, and sometimes also inflows into the ray. The inferred inflow velocities range from 3 to 30 km s$^{-1}$, consistent with the narrow opening-angle of rays, adding up to a few degrees. The density of rays is an order of magnitude larger than in the ambient corona. The density-excess measurements are compared with the results of the analytical model in which the Petschek-like reconnection geometry is applied to the vertical current sheet, taking into account the decrease of the external coronal density and magnetic field with height. The model results are consistent with the observations, revealing that the main cause of the density excess in rays is a transport of the dense plasma from lower to larger heights by the reconnection outflow

A Quantitative Model of Energy Release and Heating by Time-dependent, Localized Reconnection in a Flare with a Thermal Loop-top X-ray Source

We present a quantitative model of the magnetic energy stored and then released through magnetic reconnection for a flare on 26 Feb 2004. This flare, well observed by RHESSI and TRACE, shows evidence of non-thermal electrons only for a brief, early phase. Throughout the main period of energy release there is a super-hot (T>30 MK) plasma emitting thermal bremsstrahlung atop the flare loops. Our model describes the heating and compression of such a source by localized, transient magnetic reconnection. It is a three-dimensional generalization of the Petschek model whereby Alfven-speed retraction following reconnection drives supersonic inflows parallel to the field lines, which form shocks heating, compressing, and confining a loop-top plasma plug. The confining inflows provide longer life than a freely-expanding or conductively-cooling plasma of similar size and temperature. Superposition of successive transient episodes of localized reconnection across a current sheet produces an apparently persistent, localized source of high-temperature emission. The temperature of the source decreases smoothly on a time scale consistent with observations, far longer than the cooling time of a single plug. Built from a disordered collection of small plugs, the source need not have the coherent jet-like structure predicted by steady-state reconnection models. This new model predicts temperatures and emission measure consistent with the observations of 26 Feb 2004. Furthermore, the total energy released by the flare is found to be roughly consistent with that predicted by the model. Only a small fraction of the energy released appears in the super-hot source at any one time, but roughly a quarter of the flare energy is thermalized by the reconnection shocks over the course of the flare. All energy is presumed to ultimately appear in the lower-temperature T<20 MK, post-flare loops

Smoking is Associated with Hypermethylation of the APC 1A Promoter in Colorectal Cancer: the ColoCare Study

Smoking tobacco is a known risk factor for the development of colorectal cancer, and for mortality associated with the disease. While smoking has been reported to be associated with changes in DNA methylation in blood and in lung tumour tissues, there has been scant investigation of how epigenetic factors may be implicated in the increased risk of developing colorectal cancer. To identify epigenetic changes associated with smoking behaviours, we performed epigenome-wide analysis of DNA methylation in colorectal tumours from 36 never smokers, 47 former smokers and 13 active smokers, and adjacent mucosa from 49 never smokers, 64 former smokers and 18 active smokers. Our analyses identified 15 CpG sites within the APC 1A promoter that were significantly hypermethylated and 14 CpG loci within the NFATC1 gene body that were significantly hypomethylated (pLIS<1x10-5) in tumours of active smokers. The APC 1A promoter was hypermethylated in 7 of 36 tumours from never smokers (19%), 12 of 47 tumours from former smokers (26%), and 8 of 13 tumours from active smokers (62%). Promoter hypermethylation was positively associated with duration of smoking (Spearman rank correlation, =0.26, p=0.03) and was confined to tumours, with hypermethylation never observed in adjacent mucosa. Further analysis of adjacent mucosa revealed significant hypomethylation of four loci associated with the TNXB gene in tissue from active smokers. Our findings provide exploratory evidence for hypermethylation of the key tumour suppressor gene APC being implicated in smoking-associated colorectal carcinogenesis. Further work is required to establish the validity of our observations in independent cohorts

Results of a multi-country exploratory survey of approaches and methods for IMCI case management training

<p>Abstract</p> <p>Background</p> <p>The Integrated Management of Childhood Illness Strategy (IMCI) is effective in improving management of sick children, and thus child survival. It is currently recommended that in-service IMCI case management training (ICMT) occur over 11-days; that the participant: facilitator ratio should be ≤4:1 and that at least 30% of ICMT time be spent on clinical practice. In 2006–2007, approximately ten years after IMCI implementation, we conducted a multi-country exploratory questionnaire survey to document country experiences with ICMT, and to determine the acceptability of shortening duration of ICMT.</p> <p>Methods</p> <p>Questionnaires (QA) were sent to national IMCI focal persons in 27 purposively-selected countries. To probe further, questionnaires (QB and QC respectively) were also sent to course-directors or facilitators and IMCI trainees, selected using snowball sampling after applying pre-defined criteria, in these countries. Questionnaires gathered quantitative and qualitative data.</p> <p>Results</p> <p>Thirty-three QA, 163 QB, 272 QC and two summaries were returned from 24 countries. All countries continued to adapt course content to local disease burden. All countries offer shorter ICMT courses, ranging from 3–10 days (commonest being 5–8 days). The shorter ICMT courses offer fewer exercises, more homework, less individual feedback and reduced clinical practice (<30% time). Whereas changes to course content were usually evidence-based, changes to training methodology and course duration evolved as pressure to expand implementation mounted. Participants varied in their self-reported skill and perception about each course. However, the varied methodology and integrated approach to management of illnesses were commonly cited as strengths of ICMT, and the chart booklet and clinical practice sessions were identified as critical components of ICMT. Four themes emerged from the qualitative work, viz. the current 11-day course is too expensive and should be shortened; advocacy around IMCI should increase; content should be regularly updated, new content areas should be introduced cautiously and more attention should be paid to skills-building rather than knowledge accumulation.</p> <p>Conclusion</p> <p>Whilst the 11-day ICMT course is still recommended, as efforts intensify to increase access to quality care and meet MDG4, standardized shorter ICMT courses, that include participatory methodologies and adequate clinical practice, could be acceptable globally.</p