Fresh functional-morphological observations and theoretical considerations warrant a re-analysis of the traditional assumptions that the head skeleton of sharks consists of the chondrocranium and visceral arches and that the pectoral fin girdle is part of the appendicular skeleton. The scapulocoracoid cartilage of the Spiny Dogfish (Squalus acanthias) plays at least three major roles: (1) Asa mechanical separator between the lateral undulations of the trunk and the vertical movements of the visceral arches; (2) asa structural basis for the anchoring of the pectoral fins: and (3) as the place of origin of the cucullaris and hypobranchial muscles which not only open the jaws and expand the branchial basket, but at the same time also affect the contractions of the heart and the timing of blood flow through the gills. Hence, the scapulocoracoid cartilage is an integral part of the head. It most likely evolve d in connection with the evolution of the jaw apparatus and not simply as a part of the appendicular skeleton. Furthermore, the head is a mechanically coherent system, in which the central alimentary, circulatory, respiratory and nervous systems of the organism converge. These central feeding, respiratory and circulatory functions are not simply choreographed by the central nervous system, but are concatenated by the mechanical construction of the head itself. Sueh a conceptualization of the selachian head raises fresh questions concerning the constraints and potentialities of the evolutionary transformations of the various components of the head and pectoral appendages during the transition from aquatic pisciform to terrestrial tetrapod vertebrates.

Regulatory T cells (Treg cells), which are lymphocyte subsets capable of suppressing immune responses, appear to play a crucial role in maintaining immune homeostasis and mediating peripheral tolerance. However, Treg cells also accumulate in cancer patients and have been implicated in tumor immune escape. The forkhead box P3 (FOXP3) transcription factor is currently regarded as the most specific and reliable marker for Treg cells in men. We investigated the frequency and characterized the distribution of FOXP3(+) cells in renal cell carcinoma (RCC) patients, focusing on the tumor microenvironment. FOXP3 expression was assessed in kidney tissue samples from 32 RCC patients by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry. Both conventional and quantitative RT-PCR disclosed higher FOXP3 expression levels in RCC than in adjacent normal renal tissue. Immunohistochemical staining of FOXP3-expressing cells confirmed the accumulation of FOXP3(+) cells in tumor tissue, particularly at the border between malignant and adjacent benign kidney tissues. Our findings indicate that Treg cells accumulate at the tumor invasion zone and could thus be part of an immune escape mechanism of RCC that promotes disease progression.

ABSTRACT. Among the Rugosa operculae were developed by only a few genera. One is the slipper-shaped Calceola and another is the pyramidal shaped Goniophyllum. On the basis of biological and morphological knowledge of recent corals, the two different bauplans of the soft bodies of Calceola and Goniophyllum have been reconstructed. The soft body (i.e. the polyp) of a rugose coral is thought to have all the basic structures of anthozoan polyps: a barrel-like body shape, a¯at oral disc with tentacles, and a mouth from which a pharynx reaches inside the gastric cavity. Furthermore, as in all Anthozoa, Rugosa had internal mesenteries that act as tensile cords; during growth in the diameter further mesenteries were inserted. In contrast to all other Anthozoa, in the Rugosa new single mesenteries were added in four insertion sectors. The bauplans of Calceola and Goniophyllum differ in the pattern of mesentery insertion into these four sectors. Calceola had a serial insertion pattern and Goniophyllum had a symmetrical insertion pattern. They are representatives of the two different bauplans within the Rugosa. The lid corals are examples of convergent evolved genera; Calceola as well as Goniophyllum originated by quite simple modi®cations of the ancestral type. The peculiar shapes, the operculae and especially the straight hinges between the calyx and the lid(s) result only from mechanical necessity. Under special conditions (such as high sedimentation rates) these modi®cations of the corallites represent suitable tactics for survival.

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