Impact of the California Lead Ammunition Ban on Reducing Lead Exposure in Golden Eagles and Turkey Vultures

Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites

Is callose a barrier for lead ions entering Lemna minor L. root cells?

Plants have developed a range of strategies for resisting environmental stresses. One of the most common is the synthesis and deposition of callose, which functions as a barrier against stress factor penetration. The aim of our study was to examine whether callose forms an efficient barrier against Pb penetration in the roots of Lemna minor L. exposed to this metal. The obtained results showed that Pb induced callose synthesis in L. minor roots, but it was not deposited regularly in all tissues and cells. Callose occurred mainly in the protoderm and in the centre of the root tip (procambial central cylinder). Moreover, continuous callose bands, which could form an efficient barrier for Pb penetration, were formed only in the newly formed and anticlinal cell walls (CWs); while in other CWs, callose formed only small clusters or incomplete bands. Such an arrangement of callose within root CWs inefficiently protected the protoplast from Pb penetration. As a result, Pb was commonly present inside the root cells. In the light of the results, the barrier role of callose against metal ion penetration appears to be less obvious than previously believed. It was indicated that induction of callose synthesis is not enough for a successful blockade of the stress factor penetration. Furthermore, it would appear that the pattern of callose distribution has an important role in this defence strategy

Magnetic resonance imaging, magnetic resonance arthrography and ultrasonography for assessing rotator cuff tears in people with shoulder pain for whom surgery is being considered

Background Shoulder pain is a very common symptom. Disorders of the rotator cuff tendons due to wear or tear are among the most common causes of shoulder pain and disability. Magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and ultrasound (US) are increasingly being used to assess the presence and size of rotator cuff tears to assist in planning surgical treatment. It is not known whether one imaging method is superior to any of the others.Objectives To compare the diagnostic test accuracy of MRI, MRA and US for detecting any rotator cuff tears (i.e. partial or full thickness) in people with suspected rotator cuff tears for whom surgery is being considered.Search methods We searched the Cochrane Register of Diagnostic Test Accuracy Studies, MEDLINE, EMBASE, and LILACS from inception to February 2011. We also searched trial registers, conference proceedings and reference lists of articles to identify additional studies. No language or publication restrictions were applied.Selection criteria We included all prospective diagnostic accuracy studies that assessed MRI, MRA or US against arthroscopy or open surgery as the reference standard, in people suspected of having a partial or full thickness rotator cuff tear. We excluded studies that selected a healthy control group, or participants who had been previously diagnosed with other specific causes of shoulder pain such as osteoarthritis or rheumatoid arthritis. Studies with an excessively long period (a year or longer) between the index and reference tests were also excluded.Data collection and analysis Two review authors independently extracted data on study characteristics and results of included studies, and performed quality assessment according to QUADAS criteria. Our unit of analysis was the shoulder. for each test, estimates of sensitivity and specificity from each study were plotted in ROC space and forest plots were constructed for visual examination of variation in test accuracy. Meta-analyses were performed using the bivariate model to produce summary estimates of sensitivity and specificity. We were unable to formally investigate potential sources of heterogeneity because of the small number of studies.Main results We included 20 studies of people with suspected rotator cuff tears (1147 shoulders), of which six evaluated MRI and US (252 shoulders), or MRA and US (127 shoulders) in the same people. Many studies had design flaws, with the potential for bias, thus limiting the reliability of their findings. Overall, the methodological quality of the studies was judged to be low or unclear. for each test, we observed considerable heterogeneity in study results, especially between studies that evaluated US for the detection of full thickness tears and studies that evaluated MRA for the detection of partial thickness tears. the criteria for a positive diagnostic test (index tests and reference standard) varied between studies.Meta-analyses were not possible for studies that assessed MRA for detection of any rotator cuff tears or partial thickness tears. We found no statistically significant differences in sensitivity or specificity between MRI and US for detecting any rotator cuff tears (P = 0.13), or for detecting partial thickness tears (P = 1.0). Similarly, for the comparison between MRI, MRA and US for detecting full thickness tears, there was no statistically significant difference in diagnostic performance (P = 0.7). for any rotator cuff tears, the summary sensitivity and specificity were 98% (95% CI 92% to 99%) and 79% (95% CI 68% to 87%) respectively for MRI (6 studies, 347 shoulders), and 91% (95% CI 83% to 95%) and 85% (95% CI 74% to 92%) respectively for US (13 studies, 854 shoulders). for full thickness tears, the summary sensitivity and specificity were 94% (95% CI 85% to 98%) and 93% (95% CI 83% to 97%) respectively for MRI (7 studies, 368 shoulders); 94% (95% CI 80% to 98%) and 92% (95% CI 83% to 97%) respectively for MRA (3 studies, 183 shoulders); and 92% (95% CI 82% to 96%) and 93% (95% CI 81% to 97%) respectively for US (10 studies, 729 shoulders).Because few studies were direct head-to-head comparisons, we could not perform meta-analyses restricted to these studies. the test comparisons for each of the three classifications of the target condition were therefore based on indirect comparisons which may be prone to bias due to confounding.Authors' conclusions MRI, MRA and US have good diagnostic accuracy and any of these tests could equally be used for detection of full thickness tears in people with shoulder pain for whom surgery is being considered. the diagnostic performance of MRI and US may be similar for detection of any rotator cuff tears. However, both MRI and US may have poor sensitivity for detecting partial thickness tears, and the sensitivity of US may be much lower than that of MRI. the strength of evidence for all test comparisons is limited because most studies were small, heterogeneous and methodologically flawed, and there were few comparative studies. Well designed studies that directly compare MRI, MRA and US for detection of rotator cuff tears are needed.Universidade Federal de São Paulo, BrazilParker Institute, DenmarkOak FoundationTeesside University, UKUniversidade Federal de São Paulo, Dept Orthopaed & Traumatol, BR-04038032 São Paulo, BrazilMonash Univ, Sch Publ Hlth & Prevent Med, Dept Epidemiol & Prevent Med, Monash Dept Clin Epidemiol,Cabrini Hosp, Malvern, AustraliaUniv Birmingham, Birmingham, W Midlands, EnglandUniv Teesside, Hlth & Social Care Inst, Middlesbrough, Cleveland, EnglandUniversidade Federal de São Paulo, Dept Orthopaed & Traumatol, BR-04038032 São Paulo, BrazilWeb of Scienc