Interaction between humans and poultry, rural Cambodia

Because avian influenza H5N1 infection risks are associated with exposure to infected poultry, we conducted a knowledge, attitudes, and practices survey of poultry-handling behavior among villagers in rural Cambodia. Despite widespread knowledge of avian influenza and personal protection measures, most rural Cambodians still have a high level of at-risk poultry handling.     

Comparison of human whole blood, plasma, and serum matrices for the determination of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other fluorochemicals

Interest in human exposure to perfluorinated acids, including perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHS), perfluorooctanesulfonate (PFOS), and perfluorooctanoate (PFOA) has led to their measurement in whole blood, plasma and serum. Comparison of measurements in these different blood-based matrices, however, has not been rigorously investigated to allow for across-matrix comparisons. This research evaluated concentrations of PFBS, PFHS, PFOS, and PFOA in whole blood collected in heparin (lithium) and ethylenediamine tetraacetic acid (EDTA), plasma samples collected in heparin and EDTA, and serum (from whole blood allowed to clot). Blood samples were collected from 18 voluntary participants employed at 3M Company. Solid phase extraction methods were used for all analytical sample preparations, and analyses were completed using high-pressure liquid chromatography/tandem mass spectrometry methods. Serum concentrations ranged from: limit of quantitation (LOQ, 5 ng/mL) to 25 ng/mL for PFBS; LOQ (5 ng/mL) to 75 ng/mL for PFHS; LOQ (5 ng/mL) to 880 ng/mL for PFOS; and LOQ (5 or 10 ng/mL) to 7320 ng/mL for PFOA. Values less than the LOQ were not included in the statistical analyses of the mean of the ratios of individual values for the matrices. PFBS was not quantifiable in most samples. Serum to plasma ratios for PFHS, PFOS, and PFOA were 1:1 and this ratio was independent of the level of concentrations measured. Serum or plasma to whole blood ratios, regardless of the anticoagulant used, approximated 2:1. The difference between plasma and serum and whole blood corresponded to volume displacement by red blood cells, suggesting that the fluorochemicals are not found intracellularly or attached to the red blood cells.     

Factors associated with the technical performance of colonoscopy: An EPAGE Study

BACKGROUND: Variations in colonoscopy practice exist, which may be related to healthcare quality. AIMS: To determine factors associated with three performance indicators of colonoscopy: complete colonoscopy, adenomatous polyp diagnosis, and duration. PATIENTS: Consecutive patients referred for colonoscopy from 21 centres in 11 countries. METHODS: This prospective observational study used multiple variable regression analyses to identify determinants of the quality indicators. RESULTS: Six thousand and four patients were included in the study. Patients from private, open-access centres (odds ratio: 3.17, 95% confidence interval: 1.87-5.38) were more likely to have a complete colonoscopy than patients from public, gatekeeper centres. Patients from centres where over 50% of the endoscopists were of senior rank were roughly twice as likely to have an adenoma diagnosed, and longer average withdrawal duration (odds ratio: 1.08, 95% confidence interval: 1.07-1.09) was associated with more frequent adenoma diagnoses. Patients who had difficulty during colonoscopy had longer durations to caecum (time ratio: 2.87, 95% confidence interval: 2.72-3.01) and withdrawal durations (time ratio: 1.26, 95% confidence interval: 1.18-1.33) than patients who had no difficulties. CONCLUSIONS: Multiple factors have been identified as being associated with key quality indicators. The non-modifiable factors permit the identification of patients who may be at greater risk of not having quality colonoscopy, while changes to the modifiable factors may help improve the quality of colonoscopy.     

From the Cover: Fishing amplifies forage fish population collapses

Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches.Forage fish are small pelagic fish, such as herrings, anchovies, and sardines, that provide multiple benefits to people and marine food webs. These species support the largest fisheries in the world, accounting for 30% of global fisheries landings by weight and benefiting aquaculture and livestock industries through the production of fish meal and fish oil (1). At the same time, these species are important for marine food webs, because they provide a key linkage from lower trophic-level planktonic species to upper trophic-level predators, such as large fish, seabirds, and marine mammals (2–4). These predators also have economic value through fisheries (2), tourism (5), or nonmarket existence values (6). Collapses of forage fish populations, which have been frequent (7, 8), can, therefore, generate widespread ecological effects (9–11). Because of these concerns, there is a growing movement to develop and apply robust management approaches to forage fisheries to avoid the risk of fisheries-induced stock collapses and attendant ecological consequences (11, 12).One of the principal challenges in assessing the ecological consequences of forage fish fisheries is that these stocks undergo large cyclical fluctuations in abundance (13, 14) (Fig. 1). Fishing can potentially exacerbate naturally caused collapses, because shifts in populations’ spatial distributions coupled with fish schooling behavior allow fisheries to be economically viable, even when abundance is low (7, 15). Because of these fluctuations, standard static reference points used to judge stock status [e.g., unfished biomass (biomass that maximizes long-term sustainable yield)] have little meaning for the management of forage fish stocks. Most reference points are based on a presumed relation between population production and population biomass, but such a relationship rarely exists among these populations (Fig. S1). Moreover, these fluctuations greatly reduce our ability to ascertain effects of fishing on stock dynamics (16), and by extension, effects of fishing on dependent predators. Some have concluded that fishing acts primarily to accelerate population collapses that were destined to occur because of natural processes (7). To date, it has not been possible to determine whether fishing also makes collapses more frequent, more severe, or more prolonged.Open in a separate windowFig. 1.Examples of forage fish biomass trends showing magnitudes and characteristics of population fluctuations. Dotted lines denote the long-term mean biomass for each stock, and horizontal and vertical bars show time and biomass scale (expressed as a ratio of annual biomass to mean biomass), respectively. Time series are not aligned according to actual start and end date; β is the Fourier spectral scaling exponent, where variance scales with frequency as f ^−β. Five stocks show the range of population fluctuations from extreme long- (Tsushima Strait Pilchard) to short-term (Atlantic Menhaden) variability. Across all 40 stocks for which there were sufficiently long biomass time series to estimate β, the average coefficient of variation (CV) and β were 0.5 and 1.9, respectively. For comparison, a common decadal scale environmental index, the Pacific Decadal Oscillation (33), has β near 1.0.Here, we contribute to understanding ecological consequences of forage fish fisheries to ask how fishing has affected population characteristics that are most relevant for dependent predators. Predators are most sensitive to changes in forage fish abundance when forage abundance is low (9), and therefore, we focus on the effects of fishing with respect to the magnitude (scale of fluctuation), frequency (proportion of stocks at low abundance), and duration (number of years until recovery) of stock collapse. We compiled time series of population biomass and fisheries catches on stocks around the globe from stock assessments, restricting our analysis to 55 stocks with a time series that spanned at least 25 y (Table S1). Forage fish stocks used in this analysis included anchovies, capelin, herrings, mackerels, menhaden, sand eels, and sardines, which since 2000, supported average annual catches of 17 million tons y⁻¹ and comprised 65% of global forage fish catches (17).     

MRI of the female pelvis: a possible pitfall in the differentiation of haemorrhagic vs. fatty lesions using fat saturated sequences with inversion recovery

The use of fat-saturated techniques should be an integral part of the work-up of any T1-hyperintense structure in the female pelvis for tissue characterization and for differentiation of a fat-containing ovarian mature teratoma from a haemorrhagic lesion. Two cases with haematocolpos and haematometra are presented, respectively. The haemorrhagic content showed high signal both on T1- and T2-weighted images, whereas an unexpected signal decrease in the fat-saturated T2-weighted inversion-recovery sequence was encountered. This unspecific suppression of signal in tissues with similar T1 relaxation times as fat can lead to a diagnostic pitfall both in T1- and T2-weighted STIR pulse sequences. Furthermore, a loss of signal on T2-weighting may also be due to the phenomenon of "T2-shading" in T1-bright ovarian endometrioma. Therefore, the fat-specific spectral fat-saturation of T1-weighted images is strongly recommended for tissue characterization in gynaecological disease.     

Prospective study of surgery for left ventricular aneurysm

To assess the effects of surgery for ventricular aneurysm on left ventricular performance 18 consecutive patients referred for such surgery were Studied prospectively. The patients had the following preoperative findings: ejection fraction by Isotope ventriculogram 28± 4 percent (mean ± standard error), New York Heart Association functional class 3.6 ± 0.1 and left ventricular noncontractile area 28 ± 3 percent by the graphic integration method. Thirteen patients had both angina pectoris and congestive heart failure, two had angina alone and three had congestive heart failure alone. All patients were studied before and after operation with isotope ventriculograms at rest and during exercise and treadmill exercise tolerance tests if their clinical status permitted these studies. Five patients also had postoperative cardiac catheterization. Catheterization data were in close agreement with the results of imaging studies. In 11 patients the aneurysm was resected and in 4 H was plicated; in 3, no discrete aneurysm was found. Sixteen patients including the three with no discrete aneurysm had concomitant coronary bypass grafting. There was no operative death and one late death.After operation, all patients had significant improvement in functional class (postoperative class 2.3 ± 0.1, p < 0.005). The amount of tissue resected (percent of total left ventricular surface area) was about 50 percent of the noncontractile area visualized on contrast angiography and there was a poor correlation between these two values (r = 0.56). Only four patients (22 percent) had either an increase in ejection fraction (range 8 to 13 percent) or a greater than 10 percent reduction in end-diastolic volume. Postoperative left ventricular end-diastolic pressure was unchanged. Thus, surgery for ventricular aneurysm can be accomplished with relatively small risk. Although functional Improvement is very common, it is not related to substantial improvement in global left ventricular function.     

Blood pressure measurements in patients with Takayasu arteritis: a work of caution

Takayasu arteritis is a large vessel vasculitis among young women that affects the aorta and its branches. Disease-related subclavian or brachial obstructions can lead to hypotensive brachial blood pressure values. By contrast, arterial hypertension is also frequent in this disease, possibly unrecognized in case of solitary brachial blood pressure measurement. We present the case of a 28-year-old woman with cerebral hypoperfusion related to Takayasu arteritis. Despite "pseudo-hypotensive" brachial blood pressure values of 70 mm Hg, Doppler measurement of the ankle revealed a systolic pressure of 220 mm Hg. In Takayasu vasculitis, additional ankle pressure measurement may represent the true cardiac load and blood pressure.     

The effects of blood flow and detoxification on in vivo cholinesterase inhibition by soman in rats

The in vivo time course of cholinesterase inhibition was measured in brain, lung, spleen, hind limb skeletal muscle, diaphragm, intestine, kidney, heart, liver, and plasma of rats receiving 90 micrograms/kg soman, im. This dose of soman produced severe respiratory depression and transient hypertension, but no significant changes in the cardiac output or heart rate of anesthetized rats. The rate and maximal extent of in vivo cholinesterase inhibition by soman varied widely among the tissues. Although cardiac output was unchanged by soman administration, the blood flow in heart, brain, and lung (bronchial arterial flow and arteriovenous shunts) was increased, whereas blood flow in spleen, kidney, and skeletal muscle was decreased. The relative importance of tissue blood flow, tissue levels of cholinesterase and acetylcholinesterase, and tissue levels of soman-detoxifying enzymes (diisopropyl-fluorophosphatase and carboxylesterase) in determining the in vivo rate and maximal extent of cholinesterase inhibition was examined by multiple regression analysis. The best multiple regression model for the maximal extent of cholinesterase inhibition could explain only 63% of the observed variation. The best multiple regression model for the in vivo rate of cholinesterase inhibition contained three independent variables (blood flow, carboxylesterase, and cholinesterase) and could account for 94% of the observed variation. Of these three variables blood flow was the most important, accounting for 79% of the variation in the in vivo rate of cholinesterase inhibition. This suggests that it may be possible to use a flow-limited physiological pharmacokinetic model to describe the kinetics of in vivo cholinesterase inhibition by soman.