Fetal aortic root dilation: a prenatal feature of the Loeys-Dietz syndrome

Loeys-Dietz syndrome is a recently described autosomal dominant disorder with cardinal manifestations in cardiovascular, craniofacial and skeletal systems. Although the disease has some phenotypic overlap with Marfan syndrome, the disease, that is caused by mutations in the transforming growth factor beta-receptor 1 (TGFBR1) or transforming growth factor beta-receptor 2 (TGFBR2) genes, presents many distinctive features and a particularly aggressive cardiovascular course. We describe prenatal identification of an aortic root aneurysm in a fetus of 19 week of gestation as an early marker of Loeys-Dietz syndrome. Copyright © 2006 John Wiley & Sons, Ltd.     

Levels and trends of persistent organic pollutants in ringed seals (Phoca hispida) from Central West Greenland, with particular focus on polybrominated diphenyl ethers (PBDEs)

Polybrominated diphenyl ethers (PBDEs) and the organochlorine compounds polychlorinated biphenyls (PCBs), DDTs, HCB, chlordane-related pesticides, HCH and toxaphene were analysed in blubber of juvenile ringed seals from Central West Greenland collected between 1982 and 2006. The longest time series could be established for PBDEs, partly based on archived material, while PCBs and DDTs covered a study period from 1994-2006. All organochlorines showed decreasing trends, most pronounced for DDT and HCH with an annual change of 8%. BDE-47 had a significantly increasing trend of 5% annually. It was the only BDE congener consistently above the detection limit, with annual median concentrations between 0.78 ng/g lw to 3.54 ng/g lw, i.e. about 10 times lower than values from East Greenland observed in a similar time trend study on ringed seal blubber [Rigét F, Vorkamp K, Dietz R, Rastogi SC. Temporal trend studies on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ringed seals from East Greenland. J Environ Monit 2006; 8: 1000-5]. A clear East>West difference was also found for PCBs and DDTs, but not for chlordanes, toxaphene or HCHs. Sigma 10-PCB, Sigma DDT and Sigma Chlordanes had similar annual median concentrations, typically exceeding SigmaPBDE by two orders of magnitude. The concentrations of HCH and toxaphene were in an intermediate group, with highest annual median concentrations of 135 ng/g lw and 20 ng/g lw, respectively. For most compound groups, the circumpolar trend previously established under for example the Arctic Monitoring and Assessment Programme was confirmed, but apparently, more data are needed for chlordane-related compounds and toxaphene. Statistical analyses of the compound patterns in the ringed seal samples revealed significantly greater differences between seals from East and West than between different sampling years. Higher proportions of PCBs and DDTs and lower proportions of chlordanes and HCHs were found in seals from East Greenland than in those from West Greenland. Based on principal component analysis of individual congener and compounds, seals from East Greenland were found to contain higher proportions of the higher chlorinated CB congeners. Varying patterns between sampling locations may be caused by different exposure situations related to contaminant emissions and transport, but different feeding habits may also affect the contaminant composition.     

Developing an accident modification function for speed enforcement

This paper presents an accident modification function for speed enforcement. The function describes the percentage effect of enforcement on the number of injury accidents as a function of the relative change in the amount of enforcement. Thirteen studies that have evaluated the effects of different levels of enforcement, each containing between four and eight data points, were used as data source. A hypothesis regarding the shape of an accident modification function was formulated to help assess the plausibility of the estimated relationships. In the first stage of analysis, functions were fitted to the data points of each study by means of weighted regression analysis. Many of these functions were highly implausible and likely to be influenced by outlying data points and random variation. In the second stage of analysis, data from all studies except two were pooled and data points referring to identical or almost identical levels of enforcement were aggregated to reduce the influence of random variation. The number of data points was thus reduced from 63 to 15 and an accident modification function was fitted to the data points. The function was consistent with the hypothesis guiding the study.     

Renal lesions in Greenland sledge dogs ( Canis familiaris ) exposed to a natural dietary cocktail of persistent organic pollutants

Persistent organic pollutants such as Polychlorinated biphenyls (PCB) and dichloro diphenyl trichloroethane (DDT) are known to exert various adverse health effects in wildlife mammals. The impact from dietary intake of minke whale (Balaenoptera acutorostrata) blubber high in organohalogen and other chemical contaminants on renal morphology and function was investigated via a controlled study on West Greenland sledge dogs (Canis familiaris). Our results showed significantly higher frequencies of glomerular, tubular, and interstitial lesions in the exposed group. Furthermore, higher urine protein?:?creatinine ratio and plasma urea levels were found in the exposed group, which indicated a negative impact on kidney function via tubular and glomerular dysfunctions. The lesions were similar to those observed in top predator marine species–such as seals and polar bears–and humans exposed via diet to persistent environmental pollutants. The lesions may have impacts on the overall health of these animals. It is reasonable to suggest that chronic exposure to organic pollutants via a country diet of high trophic level marine organisms may have an impact on renal morphology and function in Arctic apex predators in general as well as Inuit people.     

Histology of Sculpin spp. in east Greenland. I. Histological measures

There is inadequate morphological nomenclature and definition of organ pathology when using wild fish in biomonitoring of environmental pollution. The aim of this investigation was to provide a guide that assesses histology of Shorthorn (Myoxocephalus scorpius) and Fourhorn (Myoxocephalus quadricornis) sculpins obtained from a study using these two fish species as bioindicator organisms to evaluate environmental impact attributed to a dumpsite located in East Greenland. Specific histopathological lesions were quantified on the basis of Bernet et al. and all lesions were photomicrographed, evaluated, and placed into specific categories of five reaction patterns. These were circulatory disturbances, regressive changes, progressive alterations, inflammation, and tumors based on anatomical location, type, and severity. This method is postulated to enable an objective assessment of the histological integrity of fish gills and liver; thus, making it possible to compare sculpin pathology and reaction patterns at different locations. Data suggest that this updated histological guide might be used for identification and quantification of histological lesions when applying sculpins in biomonitoring programs in Greenland and other Arctic regions.     

Air infiltration measurements in a home using a convenient perfluorocarbon tracer technique

Using miniature perfluorocarbon tracer (PFT) sources and miniature passive samplers, both about the size of a cigarette, tests conducted in the laboratory and in a typical home successfully demonstrated the utility of the PFT kit as a means for implementing wide-scale infiltration measurements in homes. The PFT diffusion plug source, an elastomer containing a dissolved perfluorocarbon compound, was shown to emit vapors at the rate of about 0.1 to 5 nL/min, providing steady-state concentrations in a home of about 1 to 10 pL/L, i.e., parts per trillion by volume, when one source is deployed for each 300–500 ft² (28–46 m²) of living space. The emission rate from the diffusion source was predictable, but its dependence on both temperature and time suggested the development of alternative approaches. One such alternative, a liquid PFT permeation source, had emission rates which could be tailored over the range 10–20 nL/min, were independent of age for as long as the liquid remained ( 5 yr), and had significantly lower temperature dependence. A number of passive adsorption tube samplers performed reproducibly and identically (to within ±2%–3%) in laboratory tests. Together with a programmable tracer sampler, the miniature diffusion sources and samplers were deployed in a typical home; six PFT sources were uniformly deployed, three on each level of a two-story house. Multiple location sampling, as well as sampling in rooms with and without a miniature source, demonstrated that even in a house without forced-air circulation, a well-mixed modeling approach is justified. Analyses of the tracer samplers were performed back in the laboratory with an automatic electron-capture gas-chromatography system. The effects of the inside/outside temperature differential, as well as that of an open fireplace compared with a wood-burning stove, on the measured air infiltration rates were clearly demonstrated. Comparisons of the PFT tracer method with that of the SF₆ tracer decay approach showed the results of the two methods to be identical within experimental precision. With this miniature source and sampling tracer kit, infiltration rates in the range 0.2–5 air changes per hour can be measured over time-averaged periods of as little as 1 day up to several years.