Identification of a tachykinin NK(2) receptor splice variant and its expression in human and rat tissues.

The tachykinins substance P, neurokinin A and neurokinin B are implicated in different diseases and play an important role in neuroimmunomodulation. These peptides interact with three distinct types of tachykinin receptors termed NK(1), NK(2) and NK(3). While most mammalian genes encoding G protein-coupling cell membrane receptors are intron-less, the three tachykinin receptors contain introns in their genomic structures.

Papillary carcinoma of the thyroid with mucoepidermoid differentiation.

A case of papillary carcinoma of the thyroid with mucoepidermoid differentiation is reported. There have been different hypotheses of the histogenesis of this tumor, one of which attributes the origin of the tumor to the ultimobranchial body, mainly because of the presence of neuroendocrine markers. In our case, no neuroendocrine immunohistochemical markers were demonstrated, but a progressive transition between follicular cells and mucinous cells with gradual loss of thyroglobulin immunoreactivity and acquisition of polyclonal carcinoembryonic antigen reactivity was noted.

What's new in Ewing's tumor?

Ewing's tumor is an undifferentiated neoplasm that has eluded many attempts at classification since it was first described in 1919. Even modern techniques applied to the study of series of tumors with clinical and pathologic features of Ewing's tumor have not elucidated its histogenesis. Some of these studies conclude that the cell of origin of Ewing's tumor may be a noncommitted mesenchymal cell, but many other studies suggest a neuroectodermal differentiation and further results indicate a primitive, pluripotential cell for Ewing's tumor that may differentiate in mesenchymal, epithelial and neural features.

Osteoblastoma and osteoid osteoma. Clinical and morphological features of 162 cases.

A study of 46 osteoblastomas and 91 osteoid osteomas, selected from a total of 162 cases proceeding from 15 Spanish Hospitals was done to establish epidemiological data on clinico-pathological parameters and to compare them with the findings of other authors. A comparative study between both tumors is done and emphasis is put on the discussion of aggressive osteoblastoma.