In this study, which supplements a recent article on the localization of statherin in human major salivary glands, we investigated the intracellular distribution of this peptide in minor salivary glands by immunogold cytochemistry at the electron microscopy level. In the lingual serous glands of von Ebner, gold particles were found in serous granules of all secreting cells, indicating that statherin is released through granule exocytosis. In buccal and labial glands, mostly composed of mucous tubuli, statherin reactivity was detected in the serous element, which represents only a small population of the glandular parenchyma. In these serous cells, however, statherin labeling was absent in secretory granules and restricted to small cytoplasmic vesicles near or partially fused with granules. Vesicle labeling could be related to the occurrence of an alternative secretory pathway for statherin in buccal and labial glands.

In the field of developmental biology, there is compelling evidence for a network of activity of pluripotency and stem-associated genes comprising of Oct4, Nanog and nestin. During neurogenesis, the choice between enhancement versus suppression of transcriptional modulation of these identified genes determines the balance between self-renewal neural stem cells (NSC) and immature neuronal phenotypes. By using immunocytochemistry and RT-PCR techniques, our study aims to address the question whether and to what extent mRNA and protein profiles are expressed in human fetal neurospheres obtained from cortical and striatal brain regions, both in expansion (undifferentiated cells) and differentiation conditions monitored after 1 and 4 weeks in vitro culturing. Our results clearly demonstrate the sustained presence of opposite signals: strong downregulation of Oct4 and Nanog genes in cortical differentiating cells and significant up-regulation for nestin gene both in cortical and striatal differentiating cells. Notably, by immunostaining techniques, Oct4 and Nanog protein expression have indicated the presence of both nuclear and cytoplasmic content followed by their rapid turnover (immediately after 1 week). Moreover, during the differentiation process, dissociated neurospheres displayed unexpected number of nestin positive cells accompanied by a constant level of staining intensity. In conclusion, the present study provides new insights into brain region related features in terms of Oct4, Nanog and nestin expression both at cellular and molecular level.

Human neurospheres are free-floating spherical clusters generated from a single neural stem cell and comprising cells at different stages of maturation in the neuronal and glial lineages. Although recent findings have disproved the original idea of clonally derived neurospheres according to the paradigm of one stem cell -one neurosphere, they still represent a valid model for growing neural stem cell cultures in vitro. While the immunocytochemical approach to the identification of stem cells, progenitor cells, and mature cells has been extensively used, scant data are available about the ultrastructural arrangement of different cell types within the neurosphere. This paper provides, by means of scanning electron microscopy, some new insights into the three-dimensional assembly of human neurospheres, trying to correlate some parameters such as cell density, shape and growing strategies with the immunolocalization of some antigens such as nestin, GFAP, α-internexin and βIII-tubulin. The major findings from this study are: a) regardless of the stage of in vitro maturation, the growth of the spheres is the result of mitotic divisions producing the aspect of an irregular budding mechanism in the outermost layer look like; b) analysis of the volumetric composition of the inner core has revealed the presence of two alternative shape pattern (pyramidal vs rounded cells) possibly related to both the ongoing maturation stages and GFAP and internexin expression.

The different staining patterns suggested that the two glands secrete statherin through different pathways. Prostate 71:671-674, 2011. © 2010 Wiley-Liss, Inc.

Abstract. Oxytocin is a cyclic nonapeptide whose best known effects are stimulation of uterine smooth muscle cells during labor and of milk ejection during lactation. Circulating oxytocin originates from the hypothalamus, but its production has also been documented in peripheral tissues. Furthermore, seminal plasma also contains oxytocin, but its functional role is still unknown, although its secretion is generally ascribed to the prostate. In this study, we investigated the possibility that seminal oxytocin is also secreted by other exocrine glands of the human male genital tract. Intramural (Littrè's) glands isolated from bioptic specimens of normal urethrae were processed for immunogold localization of oxytocin. Immunostaining was detected in principal cells, with gold particles specifically found on secretory granules. Basal and endocrine cells were unstained. The present findings suggest that urethral glands not only produce the mucinous layer that protects and lubricates the urethral wall, but also are potential sources of other seminal components, such as oxytocin, which probably play still unclear roles in reproductive physiology. Key words: Immunogold, Oxytocin, Urethral glands (J. Reprod. Dev. 56: [94][95][96][97] 2010) xytocin is a nonapeptide in which a disulfide bond between cysteine residues confers a cyclic structure. Its action is mediated by a transmembrane polypeptide receptor coupled with a G protein pathway, widely distributed throughout the human body [1,2]. Oxytocin is mainly studied as a hypothalamic hormone as well as vasopressin, from which it differs in two amino acids only. The best known biological effects of circulating oxytocin are those on female reproductive organs, such as stimulation of uterine contractions and of milk ejection. Moreover, effects on organs of the male genital tract have also been documented, such as penile erection and ejaculation [3,4]. In addition, a number of functions are thought to be regulated by local oxytocinergic systems, since oxytocin production has been documented in peripheral tissues [5]. In the male genital tract, paracrine secretion of oxytocin has been suggested in the testis, epididymis and prostate [1,6,7], where many functions such as cell growth, spermiation, steroidogenesis and muscle contraction could be affected [7][8][9][10]. Furthermore, seminal plasma also contains oxytocin, whose functional role still is uncertain [11][12][13]. This peptide is believed to originate from the prostate [1], but it could be also supplied by other sexual glands, which to date have not been examined in this regard. In this study, we show that the intramural glands of the human urethra (Littrè's glands) contain oxytocin-reactive material, suggesting the presence of the peptide in their exocrine secretions. Materials and MethodsSamples of the distal urethra were obtained from 4 patients aged 54-67 undergoing surgery for radical cystectomy at the Urologic Clinic of the University of Cagliari. The procedures were approved by the Local Ethics Committee, Unive...