Cellular receptors for sex steroids (SSRs) were studied in an unselected series of 55 human pituitary tumors. Cytosolic receptors for estrogen (ERcs) and progesterone (PgRcs) were determined in all cases and cytosolic androgen receptors (ARcs) in 47 cases. Nuclear receptors (ERns, PgRns, ARns) were also studied in 33 cases. ERs and PgRs were determined by an ELISA and ARs by [3H]methyltrienolone binding. Where both cytosolic and nuclear receptors were studied (n = 33), ERs, PgRs and ARs were found in at least one subcellular fraction in 66.7, 60.6 and 81.8% of cases respectively, ERs and ARs being mainly recovered from the cytosol and PgRs from the nucleus. No linear correlation was found between pre-operative plasma steroid hormones and their specific cellular receptors. Nonetheless, the differential expression of SSRs according to sex and gonadal status at the time of surgery strongly supports their regulation by the steroid environment in vivo: PgRcs were more frequent in tumors found in women (41.4 vs 15.4%, P < 0.05), whereas a high expression of ERcs and ARcs (> 15 fmol/mg protein) was more common in tumors found in men (34.5 vs 10.3%, P < 0.05 and 54.5 vs 24.0% respectively). PgRs were positively correlated with ERns, indicating the possibility of estrogen priming of their expression, and negatively correlated with ARs in nuclear fractions. SSRs appeared to be widely distributed among pituitary tumors, although, compared with other hormone-secreting groups, prolactinomas displayed a higher ERc expression (34.8 +/- 11.3 vs 4.8 +/- 5.1 fmol/mg protein, P = 0.007) and gonadotroph cell adenomas lower ARc values (1.3 +/- 0.8 vs 38.2 +/- 10.6 fmol/mg protein, P = 0.048). Microadenomas were characterized by a higher PgR expression than macroadenomas, whereas hemorrhagic (macro)adenomas were characterized by a high ER expression (> 90%). The present results indicate that most pituitary tumors are targets for sex steroids, SSR expression being partially triggered by the steroid environment itself. Possible physiopathological and therapeutic implications of these findings are discussed.

The Neotropical crab spider genera Tobias Simon, 1895 and Epicadus Simon, 1895 comprise species with remarkable somatic morphology and confounding taxonomic history. The results of our recent cladistic analysis corroborate and extend preceding taxonomic assumptions in showing that Tobias is a junior synonym of Epicadus. In the present paper the six species recently transferred from Tobias to Epicadus are redescribed. Two new species are described based on both males and females: Epicadus dimidiaster sp. nov. and Epicadus tigrinus sp. nov.; the male of Epicadus granulatus Banks, 1909 is described for the first time. The diagnosis of the genus is revised, an identification key is provided, and information on geographical distribution is updated. Epicadus now comprises eleven species.

The present paper presents a cladistic analysis of the spider genus Tobias Simon, 1895. The analyses were based on a matrix with 29 terminal taxa scored for 86 morphological characters, with a dataset tested under two methodologies for character weighting (i.e. equal and implied weighting). Both analyses supported the paraphyletic relationship of Tobias with Epicadus Simon, 1895, with the former considered a junior synonym of the latter (new synonymy). Onocolus, Epicadinus and Epicadus form a clade supported by two synapomorphies, corroborating previous taxonomic assumptions regarding the proximity of these genera. Epicadus has two lineages: the ‘pustulosus clade’, comprising bark-like individuals that camouflage themselves on tree trunks and branches, and the ‘heterogaster clade’, which consists of a group of spiders that present a wide range of polychromatism and use flowers as hunting sites. Synonymies are presented and a new combination for all species previously assigned as part of Tobias is proposed. Epicadus now comprises nine species.

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The spider genus Enna is revised and the five previously known species [E. estehcmemis (Simon 1898) (Venezuela), £■. /»///«;/ (Simon 1898) (Panama, Colombia), E. minor Petrunkevitch 1925 (Panama, Colombia), E. nesioles Chamberlin 1925 (Panama) and E. velo.x O. Pickard-Cambridge 1897 (type species) (Mexico)] are redescribed. Dossmus rediiiulans Platnick, 1993 is transferred to Enna and is redescribed and illustrated. Descriptions of 18 new species include the following: E. haeza (Ecuador), E. hartica (Guyana), E. braslandia. (Brazil), E. honaldoi (Brazil) E. caliensis (Colombia), E. chickeringi (Honduras), E. colonche (Ecuador), E. eberhardi (Costa Rica, Panama), E. harct (Peru), E. biunmco (Peru), E. Iinarinillu (Bolivia), E. igarape (Brazil), E. knyuwiniensis (Guyana), E. nuiyu (Honduras, Panama), E. paraensis (Brazil), E. pecki (Costa Rica), E. riolopo (Ecuador) and E. rothi (Ecuador). The type of E. approxinuita (O. Pickard-Cambridge), collected in Bugaba, Panama, is based on a juvenile and is considered as a nonien dubiicm. Similarities in the geographical distributions of species of Enna with the distributions of species in the genera Trechalea and Hesydrus are noted.

Three species of the genus Allocosa Banks, 1900 from southern South America are redescribed: Allocosa alticeps (Mello-Leitão, 1944), A. brasiliensis (Petrunkevitch, 1910) and A. senex (Mello-Leitão, 1945). The female of A. senex is described for the first time and the species is revalidated. A new species, A. marindia sp. nov. from southern Uruguay and southern Brazil is described. The new species is distinguished by the flattened terminal apophysis of the male bulb and the conspicuous pointed projections on the posterior margin of the female epigynum. The species inhabits in sandy estuarine and oceanic coasts with psammophile vegetation.

The males of Tobias caudatus Mello-Leitão, 1929 and Tobias pustulosus Simon, 1929 are described for the first time, females are redescribed and both sexes are illustrated. New distribution records are presented for both species. Tobias monstruosus Mello-Leitão, 1929 is considered a junior synonym of T. pustulosus. The types of Tobias albovittatus Caporiacco, 1954, and Tobias gradiens Mello-Leitão, 1929 are lost, and Tobias albicans Mello-Leitão, 1929 and Tobias corticatus Mello-Leitão, 1917 are known only from poorly preserved specimens, thus they all are considered nomina dubia.

A new caponiid genus, Nyetnops, is described to contain a remarkable new species, N. guarani from Brazil. These spiders, which have a bizarrely elongated male palp, have the subsegmented tarsi typical of the Nopinae, but lack the additional leg modifications found in those taxa. They may therefore represent the sister group of the other described nopine genera.