Alzheimer's disease: spect and pet tracers for beta-amyloid imaging.

The definite diagnosis of Alzheimer's disease (AD) is based on the detection of beta amyloid (Aß) plaques and neurofibrillary tangles (NFTs) - which are the pathological hallmarks of the disease- in the postmortem brains. Although regional Cerebral Blood Flow (rCBF) and Cerebral Glucose Metabolism (CGM) abnormalities have already been studied in AD patients with Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET), the development of specific imaging agents for direct mapping of Aß plaques in the living brain, is a great challenge. Aß probes could significantly contribute to the early diagnosis of AD, the elucidation of the underlying neuropathological processes and the evaluation of anti-amyloid therapies which are currently under investigation. The development of SPECT and PET tracers for Aß imaging represents an active area in radiopharmaceutical design. A substantial number of potential Aß imaging radioligands have been designed and used in-vitro. They are either monoclonal antibodies to Aß and radiolabeled Aß peptides, or derivatives of histopathological stains such as Congo red (CR), chrysamine-G (CG) and Thioflavin T (TT). Though, only few of them, that display high binding affinity to Aß as well as sufficient brain penetration, have been used primarily in in-vivo studies and to a smaller degree on human subjects. Since Aß plaques are not homogenous and contain multiple binding sites that can accommodate structurally diverse compounds, they offer flexibility in designing various different probes, as potential amyloid imaging agents.

EuroBionet: a pan-European biomonitoring network for urban air quality assessment.

EuroBionet, the 'European Network for the Assessment of Air Quality by the Use of Bioindicator Plants', is an EU-funded cooperative project currently consisting of public authorities and scientific institutes from 12 cities in 8 countries. In 2000, the bioindicator plants tobacco (Nicotiana tabacum Bel W3), poplar (Populus nigra 'Brandaris'), spiderwort (Tradescantia sp. clone 4430), Italian rye grass (Lolium multiflorum italicum) and curly kale (Brassica oleracea acephala) were exposed to ambient air at 90 monitoring sites according to standardised methods. Visible injuries and growth parameters were assessed and the accumulation of toxic substances in leaves determined. The exposure of tobacco resulted in a gradient with low levels of ozone-induced foliar injury in N and NW Europe, and medium to high values in the southern and central regions. The results of heavy metal and sulphur analyses in rye grass samples generally showed low to very low sulphur and low to medium heavy metal concentrations in leaves. In some cities, however, local hot spots of heavy metal contamination were detected. Analyses of the PAH contents in curly kale leaves gave low to medium values, with locally elevated levels at traffic-exposed sites.

Scleroderma heart disease: an unusual cause of positive antimyosin cardiac imaging.

In-antimyosin scintigraphy offers a valuable noninvasive method for early detection of clinically silent cardiac involvement in patients with systemic sclerosis, even in the absence of left ventricular dysfunction. In these patients with positive antimyosin study results, intense pharmacologic treatment with vasodilators may be warranted.