Pleomorphic adenoma of the parotid gland: histopathologic analysis of the capsular characteristics of 218 tumors

BACKGROUND: Histopathologic features of the capsule may have an impact on the recurrence rate of pleomorphic adenomas. METHODS: Retrospective (n = 154) and prospective (n = 64) histologic analysis of the capsular characteristics such as incompleteness, tumor penetration, pseudopodia, and satellite tumors of 218 pleomorphic adenomas. RESULTS: In 160 of the 218 (73%) pleomorphic adenomas, 1 or more capsular characteristics such as incomplete capsule (33%), capsule penetration (26%), pseudopodia (40%), and satellite nodules (13%) were detected. Incomplete capsule and satellite tumors were most frequently seen in the stroma-rich (myxoid) subtype. Capsular penetration and pseudopodia were significantly more common in the prospective group than in the retrospective group (p < .05/<.05). CONCLUSION: Pseudopodia and satellite tumors were more common than reported in the literature. If left in the surrounding salivary gland tissue at surgery, they can lead to recurrences of pleomorphic adenomas of the parotid gland.

Age of cichlids: new dates for ancient lake fish radiations

Timing divergence events allow us to infer the conditions under which biodiversity has evolved and gain important insights into the mechanisms driving evolution. Cichlid fishes are a model system for studying speciation and adaptive radiation, yet, we have lacked reliable timescales for their evolution. Phylogenetic reconstructions are consistent with cichlid origins prior to Gondwanan landmass fragmentation 121-165 MYA, considerably earlier than the first known fossil cichlids (Eocene). We examined the timing of cichlid evolution using a relaxed molecular clock calibrated with geological estimates for the ages of 1) Gondwanan fragmentation and 2) cichlid fossils. Timescales of cichlid evolution derived from fossil-dated phylogenies of other bony fishes most closely matched those suggested by Gondwanan breakup calibrations, suggesting the Eocene origins and marine dispersal implied by the cichlid fossil record may be due to its incompleteness. Using Gondwanan calibrations, we found accumulation of genetic diversity within the radiating lineages of the African Lakes Malawi, Victoria and Barombi Mbo, and Palaeolake Makgadikgadi began around or after the time of lake basin formation. These calibrations also suggest Lake Tanganyika was colonized independently by the major radiating cichlid tribes that then began to accumulate genetic diversity thereafter. These results contrast with the widely accepted theory that diversification into major lineages took place within the Tanganyika basin. Together, this evidence suggests that ancient lake habitats have played a key role in generating and maintaining diversity within radiating lineages and also that lakes may have captured preexisting cichlid diversity from multiple sources from which adaptive radiations have evolved.

Unfair Advantage: An Intriguing Example of Legal Transformation in the Swiss Private Law

This paper demonstrates a mixed approach to the theme of the instrumentality of law by both analysing the goal of a legal transformation and the techniques adapted to achieve it. The correct recognition of a certain practical necessity has lead the Swiss Federal Tribunal to an intriguing judgement “Fussballclub Lohn-Fall” of 1997. The legal remedies provided for cases of unfair advantage have been then creatively modified praeter legem. The adaptation was strongly influenced by foreign legal patterns. The Swiss Code of Obligations of 1911 provides a norm in art. 21 on unfair advantage (unconscionable contract), prescribing that if one party takes unjustified advantage over the weaknesses of another in order to receive an excessive benefit, such a contract is avoidable. Its wording has been shaped over a hundred years ago and still remains intact. However, over the course of the 20th century the necessity for a more efficient protection has arisen. The legal doctrine and jurisprudence were constantly pointing out the incompleteness of the remedies provided by art. 21 of the Code of Obligations. In the “Fussballclub Lohn-Fall” (BGE 123 III 292) the Swiss Federal Tribunal finally introduced the possibility to modify the contract. Its decision has been described as “a sign of the zeitgeist, spirit of the time”. It was the Swiss legal doctrine that has imposed the new measure under the influence of the German “quantitative Teilnichtigkeit” (quantitative partial nullity). The historical heritage of the Roman laesio enormis has also played its role.