Mechanism of primitive duct formation in the pancreas and submandibular glands: a role for SDF-1

BACKGROUND: The exocrine pancreas is composed of a branched network of ducts connected to acini. They are lined by a monolayered epithelium that derives from the endoderm and is surrounded by mesoderm-derived mesenchyme. The morphogenic mechanisms by which the ductal network is established as well as the signaling pathways involved in this process are poorly understood. RESULTS: By morphological analyzis of wild-type and mutant mouse embryos and using cultured embryonic explants we investigated how epithelial morphogenesis takes place and is regulated by chemokine signaling. Pancreas ontogenesis displayed a sequence of two opposite epithelial transitions. During the first transition, the monolayered and polarized endodermal cells give rise to tissue buds composed of a mass of non polarized epithelial cells. During the second transition the buds reorganize into branched and polarized epithelial monolayers that further differentiate into tubulo-acinar glands. We found that the second epithelial transition is controlled by the chemokine Stromal cell-Derived Factor (SDF)-1. The latter is expressed by the mesenchyme, whereas its receptor CXCR4 is expressed by the epithelium. Reorganization of cultured pancreatic buds into monolayered epithelia was blocked in the presence of AMD3100, a SDF-1 antagonist. Analyzis of sdf1 and cxcr4 knockout embryos at the stage of the second epithelial transition revealed transient defective morphogenesis of the ventral and dorsal pancreas. Reorganization of a globular mass of epithelial cells in polarized monolayers is also observed during submandibular glands development. We found that SDF-1 and CXCR4 are expressed in this organ and that AMD3100 treatment of submandibular gland explants blocks its branching morphogenesis. CONCLUSION: In conclusion, our data show that the primitive pancreatic ductal network, which is lined by a monolayered and polarized epithelium, forms by remodeling of a globular mass of non polarized epithelial cells. Our data also suggest that SDF-1 controls the branching morphogenesis of several exocrine tissues.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Induction, expression and characterisation of laccase genes from the marine-derived fungal strains Nigrospora sp. CBMAI 1328 and Arthopyrenia sp. CBMAI 1330

The capability of the fungi Nigrospora sp. CBMAI 1328 and Arthopyrenia sp. CBMAI 1330 isolated from marine sponge to synthesise laccases (Lcc) in the presence of the inducer copper (110 M) was assessed. In a liquid culture medium supplemented with 5 M of copper sulphate after 5 days of incubation, Nigrospora sp. presented the highest Lcc activity (25.2 UL1). The effect of copper on Lcc gene expression was evaluated by reverse transcriptase polymerase chain reaction. Nigrospora sp. showed the highest gene expression of Lcc under the same conditions of Lcc synthesis. The highest Lcc expression by the Arthopyrenia sp. was detected at 96 h of incubation in absence of copper. Molecular approaches allowed the detection of Lcc isozymes and suggest the presence of at least two undescribed putative genes. Additionally, Lcc sequences from the both fungal strains clustered with other Lcc sequences from other fungi that inhabit marine environments.M. Passarini was supported by Ph.D. grant from FAPESP (2008/06720-7), Sao Paulo, Brazil. The authors thank FAPESP for financial support (BIOTA-FAPESP grant 2010/50190-2 and FAPESP grant 2013/19486-0) and Roberto G.S. Berlinck and CEBIMAR for the support related to samples collecting. L.D. Sette thanks CNPq for Productivity Fellowships 304103/2013-6

The dream-lag effect: Selective processing of personally significant events during Rapid Eye Movement sleep, but not during Slow Wave Sleep

Incorporation of details from waking life events into Rapid Eye Movement (REM) sleep dreams has been found to be highest on the night after, and then 5–7 nights after events (termed, respectively, the day-residue and dream-lag effects). In experiment 1, 44 participants kept a daily log for 10 days, reporting major daily activities (MDAs), personally significant events (PSEs), and major concerns (MCs). Dream reports were collected from REM and Slow Wave Sleep (SWS) in the laboratory, or from REM sleep at home. The dream-lag effect was found for the incorporation of PSEs into REM dreams collected at home, but not for MDAs or MCs. No dream-lag effect was found for SWS dreams, or for REM dreams collected in the lab after SWS awakenings earlier in the night. In experiment 2, the 44 participants recorded reports of their spontaneously recalled home dreams over the 10 nights following the instrumental awakenings night, which thus acted as a controlled stimulus with two salience levels, high (sleep lab) and low (home awakenings). The dream-lag effect was found for the incorporation into home dreams of references to the experience of being in the sleep laboratory, but only for participants who had reported concerns beforehand about being in the sleep laboratory. The delayed incorporation of events from daily life into dreams has been proposed to reflect REM sleep-dependent memory consolidation. However, an alternative emotion processing or emotional impact of events account, distinct from memory consolidation, is supported by the finding that SWS dreams do not evidence the dream-lag effect

Evaluation of a new community-based curriculum in disaster medicine for undergraduates

BACKGROUND: Nowadays, many medical schools include training in disaster medicine in undergraduate studies. This study evaluated the efficacy of a disaster medicine curriculum recently designed for Saudi Arabian medical students. METHODS: Participants were 15 male and 14 female students in their fourth, fifth or sixth year at Jazan University Medical School, Saudi Arabia. The course was held at the Research Center in Emergency and Disaster Medicine and Computer Sciences Applied to the Medical Practice in Novara, Italy. RESULTS: The overall mean score on a test given before the course was 41.0 % and it increased to 67.7 % on the post-test (Wilcoxon test for paired samples: z = 4.71, p < 0.0001). There were no significant differences between the mean scores of males and females, or between students in their fourth, fifth or sixth year of medical school. CONCLUSIONS: These results show that this curriculum is effective for teaching disaster medicine to undergraduate medical students. Adoption of this course would help to increase the human resources available for dealing with disaster situations

A new reconstruction of the iridopteridalean Ibyka amphikoma Skog et Banks from the Middle Devonian of Gilboa, New York State

Premise of research. Clarifying the basic anatomy and morphology of Devonian fossils is essential for understanding the origin and radiation of land plants in deep time. Iridopteridales is a major Devonian plant group for which there is no presently established whole-plant concept. Methodology. The type material of the iridopteridalean Ibyka amphikoma Skog et Banks was reprepared and redescribed to clarify the details of its branching patterns and enable comparison to the previously described anatomy. Pivotal results. At least three orders of branching are known. Insertions of laterals are dominantly whorled, sometimes imperfectly, with distinct internodes. Within a whorl, branches may substitute for dichotomous appendages, with the latter more numerous. A new reconstruction is presented. On the basis of the partially preserved anatomy and the comparison to anatomically preserved Iridopteridales, we infer that traces to the branches and appendages are emitted one from each arm of a multiribbed actinostele. This pattern contrasts with that of the only other iridopteridalean preserved both anatomically and morphologically, Compsocradus laevigatus Berry et Stein, in which traces are emitted from alternate ribs in each whorl, with angular offsets between adjacent whorls. Conclusions. This basic understanding of the essentially whorled organization of Iridopteridales, as well as their overall morphology and anatomy, will benefit attempts to infer the broader phylogeny of early land plants, including the origins of horsetails and ferns