Search

Purpose: Patients with invasive fungal infections are often treated initially with conventional amphotericin B deoxycholate (CAB), followed by a switch to lipid-based formulations of amphotericin B (LF-AMB). Our study examined adverse events and hospital length of stay (LOS) among adults who received LF-AMB exclusively or CAB followed by LF-AMB (CAB/LF-AMB).Methods: Data were extracted from the Cerner Health Facts database. The study included adults with evidence of infection by Aspergillus, Candida, or Cryptococcus in addition to either renal insufficiency, a clinical condition suggesting intolerance to CAB, or CAB exposure within 90 days of admission. Nephrotoxicity was defined as a serum creatinine (SCr) level exceeding a 100% increase from baseline and an absolute level above 1.2 mg/dL. We used a hierarchical mixed-effect logistic regression model with nephrotoxicity as the outcome for the multivariate analysis.Results: The study included 327 LF-AMB and 81 CAB/LF-AMB patients with similar demographics and baseline SCr values. The mean pre-to-post percentage increase in SCr levels was greater for CAB/LF-AMB (122.9%) compared with LF-AMB (62.2%) (P < 0.001). The multivariate-adjusted odds ratio of nephrotoxicity was 5.93, for a 95% confidence interval of 2.92 to 12.05 (P < 0.001) for CAB/LF-AMB compared with LF-AMB. Hypokalemia, hypomagnesemia, and infusion-related reactions were more frequent with CAB/LF-AMB. Compared with the LF-AMB group, the CAB/LF-AMB patients had a longer post-amphotericin B LOS (24.1 days vs. 15.7 days, respectively; P < 0.001), with a marginal effect of 4.5 days longer for those receiving CAB/LF-AMB (P = 0.016).Conclusion: In this retrospective study, we noted a significantly longer post-amphotericin B LOS and a greater frequency of adverse events, including nephrotoxicity, for patients whose initial treatment was CAB and who were switched to LF-AMB, compared with patients who received LF-AMB only. [ABSTRACT FROM AUTHOR]

Abstract Biologists and policy makers continue to seek environmental correlates of mercury bioavailability in aquatic ecosystems. In this study, we assessed the effects of drainage basin, habitat type, size class, and sex on mercury concentrations in the northern crayfish, Orconectes virilis (Hagen). Drainage basin, habitat type, and size class had significant effects on mercury concentration in crayfish tail muscle even though animals from roughly half the sites examined had mean mercury values at or below expected background levels. The low observed mercury values in crayfish tail muscle indicate a low consumptive risk. Contrary to expectations, crayfish from brooks had higher mercury concentrations than animals from other habitat types, possibly as a result of point source contamination or varying diet compositions among habitats. We suggest that crayfish represent a good indicator of mercury bioavailability in aquatic ecosystems and provide a synthesis for lower food webs. Our understanding of mercury dynamics in lower food webs has been hindered by an under appreciation of the complexity in foraging habits of macroinvertebrates. Further studies focusing on benthos with well-understood life histories and foraging behavior are essential to improve our understanding of mercury transfer and bioavailability through aquatic systems. [ABSTRACT FROM AUTHOR]

Abstract Aquatic ecosystems have received mercury released from anthropogenic sources. The northeast region of North America is at especially high risk because of local and regional emission sources, prevailing wind patterns, and certain hydrological and biogeochemical features. Here we examine regional variation in total mercury (Hg) in brain, liver, and fur from otter and mink collected across New York, New England, and Nova Scotia. Gender and age are examined as factors potentially affecting Hg tissue levels. In addition, temporal relationships are analyzed for New York as well as correlative relationships for tissues from Maine. Animals were collected from 1982 to 2003, mostly from licensed trappers. Liver was the only tissue from otter that exhibited significant regional variation (New York versus Maine) in Hg concentration. Mercury concentration was significantly related to age but not to gender for otter. All tissues in mink exhibited significant, but inconsistent, regional variation in total Hg concentration, with the highest mean Hg concentration in liver samples from Massachusetts/Connecticut. Female mink had significantly greater Hg concentrations in liver than males. Total Hg concentration in the liver of both otter and mink from New York decreased significantly with time. Correlations among tissues for Hg concentration were stronger for male and female mink and male otter than female otter from Maine. [ABSTRACT FROM AUTHOR]

Abstract A large data set of over 4,700 records of avian mercury (Hg) levels in northeastern North America was compiled and evaluated. As Hg emissions remain poorly regulated in the United States and Canada, atmospheric deposition patterns and associated ecological responses continue to elicit interest by landscape managers, conservation biologists, policy makers, and the general public. How avian Hg exposure is interpreted greatly influences decision-making practices. The geographic extent and size of this data set is valuable in understanding the factors that affect the exposure of Hg to birds. Featured are differences found among tissues, major aquatic habitats and geographic areas, between age class and gender, and among species. While Hg concentrations in egg and blood reflect short-term Hg exposure, Hg concentrations in liver and feather provide insight into long-term Hg exposure. Blood is a particularly important matrix for relating site-specific exposure to methylmercury (MeHg). The level of MeHg is generally 5–10x greater in adults compared to nestlings. Age also influences MeHg bioaccumulation, particularly for individuals where MeHg intake exceeds elimination. Gender is of interpretive concern when evaluating Hg exposure for species exhibiting sexual dimorphism and niche partitioning. Based on two indicator species, the belted kingfisher (Ceryle alcyon) and bald eagle (Haliaeetus leucocephalus), we found MeHg availability increased from marine, to estuarine and riverine systems, and was greatest in lake habitats. A large sample of >1,800 blood and egg Hg levels from the common loon (Gavia immer) facilitated a suitable comparison of geographic differences. Although some clusters of highly elevated Hg exposure (i.e., blood levels >3.0 µg/g, ww and egg levels >1.3 µg/g, ww) were associated with hydrological and biogeochemical factors known to increase MeHg production and availability, others were not. Geographic areas without a relationship between Hg exposure and biogeochemical processes were associated with emission or waterborne point sources. Differences in Hg exposure among species are primarily correlated with trophic position and availability of MeHg. Although piscivorous species were repeatedly shown to have some of the highest MeHg levels of the 38 species analyzed, insectivorous birds in both aquatic and terrestrial habitats (such as montane areas) were also found with elevated MeHg levels. A better understanding of the factors confounding interpretation of Hg exposure provides an effective basis for choice of indicator species and tissues according to 12 selected scenarios. This and the national need for spatiotemporal monitoring of MeHg availability require careful consideration of indicator species choice. Only then will local, regional, continental, and even global monitoring efforts be effective. [ABSTRACT FROM AUTHOR]

Abstract Anthropogenic input of mercury (Hg) into the environment has elevated risk to fish and wildlife, particularly in northeastern North America. Investigations into the transfer and fate of Hg have focused on inhabitants of freshwater aquatic ecosystems, as these are the habitats at greatest risk for methylmercury (MeHg) biomagnification. Deviating from such an approach, we documented MeHg availability in a terrestrial montane ecosystem using a suite of insectivorous passerines. Intensive and extensive sampling of Bicknell’s thrush (Catharus bicknelli) indicated significant heterogeneity in MeHg availability across 21 mountaintops in northeastern North America. Southern parts of the breeding range tended to be at greater risk than northern parts. Mean blood Hg concentrations for Bicknell’s thrush at 21 distinct breeding sites ranged from 0.08 to 0.38 ug/g (ww) and at seven Greater Antillean wintering sites ranged from 0.03 to 0.42 ug/g (ww). Overall concentrations were significantly greater in wintering than in breeding areas. Mercury exposure profiles for four passerine species on Mt. Mansfield, Vermont indicated greatest MeHg uptake in Bicknell’s thrush and yellow-rumped warbler (Dendroica coronata) and lowest in blackpoll warbler (Dendroica striata) and white-throated sparrow (Zonotrichia albicollis). The MeHg and total Hg ratio in blood in these four species was nearly 1:1. There was no correlation between blood and feather Hg concentrations in breeding Bicknell’s thrush, in part because of apparent retention of winter Hg body burdens, within-season variation of MeHg availability, and confounding factors such as influences from age. Adult thrushes had significantly higher concentrations of feather Hg than did young-of-the-year. Although individual patterns of inter-year feather Hg concentrations were disordered, some individuals exhibited bioaccumulation of MeHg. Female blood Hg concentrations were significantly lower than males’, in part because females have additional depurating mechanisms through eggs. Older male Bicknell’s thrushes that breed in New England are therefore likely at greatest risk. Mechanisms for Hg methylation in montane areas without standing water are not yet fully understood. However, recent studies indicate that MeHg is present in forest tree leaves and leaf detritus; saturated soils and other moist microhabitats may also contribute to MeHg availability. Our finding of a correlation between regional litterfall Hg flux patterns and Bicknell’s thrush blood Hg concentrations demonstrates on-site availability of MeHg. Further investigations into MeHg availability in montane environments are recommended to assess risk to insectivorous passerines, particularly the Bicknell’s thrush. [ABSTRACT FROM AUTHOR]

The study describes how a computer game was used as a kinaesthetic training aid to resolve sensorimotor functional deficits in a patient recovering from a subarachnoid haemorrhage. The game required the patient, a 34-year-old male, to initiate the appropriate finger movements (as used in his daily work) in response to a visual stimulus, and by the recording and display of temporal reaction times, allowed him to quantify and improve his alacrity. Comparisons between pre- and post-training data showed thatthe patientsignificantly reduced both the number of moves required and the time taken to complete a game. The study convincingly demonstrates that individually ''tailored" and extensively practised training procedures can reduce functional deficits and even enable full occupational rehabilitation. [ABSTRACT FROM AUTHOR]