Finger chondroid syringoma as a hypoechoic subcutaneous nodule in ultrasound.

Chondroid syringoma (CS) is an uncommon, benign epithelial skin mixed tumor. It is often located in the head and neck and is unusual in other parts of the body. It may be seen as a skin or soft tissue tumor. We present findings on high-resolution ultrasound and histology in a case of benign CS located on the right index finger. High-resolution ultrasound showed a solid hypoechoic, well-defined subcutaneous mass, adjacent to the tendon. Complete surgical excision was performed, and histopathology demonstrated an apocrine mixed tumor (CS). Although CS histological findings are well described, radiological features have been reported only in few cases and mainly in magnetic resonance. Chondroid syringoma should be suspected by high-resolution ultrasound as a differential diagnosis for a solid slow-growing soft tissue nodule in a finger, especially if the lesion has no contact with the underlying tendon.

Species richness and adaptive capacity in animal communities: lessons from China.

Climate change is already threatening the long-term viability of many important protected areas, and as global warming accelerates this will increase. Lowered water tables, melting permafrost, changing vegetation zones, combined with the fragmentary distribution of wilderness areas, will cause a wave of local extinctions as species fail to adapt to changing conditions in time or fail to move as climate zones advance across the face of the continents. Ecologists can predict and even model likely scenarios, but can we do anything to help safeguard valuable biodiversity or must we passively document Earth's changes and accept these losses? Studies of the extraordinary species richness of the Hengduan Mountains and the Qionglai Mountain ranges of South-West China and of the Changbaishan Mountains in North-East China give us some optimism. This paper provides an explanation for the high species richness in these ranges and identifies design principles that can be used in the selection of protected areas or in the revision of existing protected area boundaries to enhance their ecological resilience and allow them to maintain higher levels of biological diversity under conditions of climate change or other disturbance.

A rationale for determining, testing, and controlling specific impurities in pharmaceuticals that possess potential for genotoxicity.

The synthesis of pharmaceutical products frequently involves the use of reactive reagents and the formation of intermediates and by-products. Low levels of some of these may be present in the final drug substance and drug product as impurities. Such chemically reactive impurities may have at the same time the potential for unwanted toxicities including genotoxicity and carcinogenicity and hence can have an impact on product risk assessment. This paper outlines a procedure for testing, classification, qualification, toxicological risk assessment, and control of impurities possessing genotoxic potential in pharmaceutical products. Referencing accepted principles of cancer risk assessment, this document proposes a staged threshold of toxicological concern (TTC) approach for the intake of genotoxic impurities over various periods of exposure. This staged TTC is based on knowledge about tumorigenic potency of a wide range of genotoxic carcinogens and can be used for genotoxic compounds, for which cancer data are limited or not available. The delineated acceptable daily intake values of between approximately 1.5 microg/day for approximately lifetime intake and approximately 120 microg/day for < or = 1 month are virtually safe doses. Based on sound scientific reasoning, these virtually safe intake values do not pose an unacceptable risk to either human volunteers or patients at any stage of clinical development and marketing of a pharmaceutical product. The intake levels are estimated to give an excess cancer risk of 1 in 100,000 to 1 in a million over a lifetime, and are extremely conservative given the current lifetime cancer risk in the population of over 1 in 4 (http://seer.cancer.gov/statfacts/html.all.html). The proposals in this document apply to all clinical routes of administration and to compounds at all stages of clinical development. It is important to note that certain types of products, such as those for life-threatening indications for which there are no safer alternatives, allow for special considerations using adaptations of the principles outlined in this paper.