Placenta-derived stem cells: new hope for cell therapy?

An urgent current need in regenerative medicine is that of identifying a plentiful, safe and ethically acceptable stem cell source for the development of therapeutic strategies to restore functionality in damaged or diseased organs and tissues. In this context, human term placenta represents a prime candidate, as it is available in nearly unlimited supply, is ethically problem-free and easily procured. Placental cells display differentiation capacity toward all three germ layers, while also displaying immunomodulatory effects, therefore supporting the possibility that they could be applied in an allogeneic transplantation setting. Although promising data have been reported to date, further study is required to fully characterize the differentiation potential of placenta-derived cells and to identify their possible clinical applications. Here, we provide a snapshot of current knowledge regarding the potential of cells from the amniotic membrane of human term placenta to address current shortcomings in the field of regenerative medicine.     

The use of Ethics Decision‐Making Frameworks by Canadian Ethics Consultants: A Qualitative Study

In this study, Canadian healthcare ethics consultants describe their use of ethics decision‐making frameworks. Our research finds that ethics consultants in Canada use multi‐purpose ethics decision‐making frameworks, as well as targeted frameworks that focus on reaching an ethical resolution to a particular healthcare issue, such as adverse event reporting, or difficult triage scenarios. Several interviewees mention the influence that the accreditation process in Canadian healthcare organizations has on the adoption and use of such frameworks. Some of the ethics consultants we interviewed also report on their reluctance to use these tools. Limited empirical work has been done previously on the use of ethics decision‐making frameworks. This study begins to fill this gap in our understanding of the work of healthcare ethics consultants.     

The karyotype of the Middle-African hedgehog Atelerix albiventris Wagner, 1841 and its cytotaxonomical relationships to other Erinaceinae (Insectivora: Erinaceidae)

Like other hedgehog species investigated hitherto, also the Middle African species Atelerix albiventris has a diploid number of 48 chromosomes. However, Aethechinus and Atelerix display quite distinct cytogenetic characteristics compared to the hedgehog genera Erinaceus, Hemiechinus and Paraechinus. Individual chromosome structures and reactivities permit the recognition of similarities to the Algerian hedgehog Aethechinus algirus and indicate their close relationship.Nevertheless, the proposal by Corbet (1988) to merge the two taxa into one genus, which is contrary to Robbins and Setzer (1985), remains to be clarified by further investigations.     

Oligogalacturonides stimulate pericycle cell wall thickening and cell divisions leading to stoma formation in tobacco leaf explants

Novel developmental events induced by micromolar concentrations of oligogalacturonides (OGs) in tobacco leaf explants cultured in vitro are described. Oligogalacturonides induced acceleration and synchronization of the mitotic activity of guard-cell precursors in the epidermis. In explants cultured for 24 h in the presence of OGs, the number of stomatal mitoses was higher than that observed in explants cultured in the absence of OGs; however, at the end of the culture period the density of mature stomata did not vary upon OG treatment. The OG-induced activation of stomatal mitosis was reduced by exogenously added indole-3-acetic acid (IAA). Oligogalacturonides also enhanced mean wall thickness, mainly due to cellulose deposition, of foliar pericycle cells, as well as the number of extra-thick-walled pericycle cells; the pericycle thus formed a sheath surrounding phloem and xylem. Indole-3-acetic acid decreased the number of extra-thick-walled cells forming in the presence of OGs but did not influence wall thickness. Moreover, OGs inhibited the stimulation of mitotic activity of phloem parenchyma cells (vascular mitoses) induced by auxin, leading to a nearly complete inhibition of IAA-induced formation of callus and of meristemoids of indirect origin. Instead, OGs did not influence mitotic activity occurring in the absence of auxin. All in all, our results provide further evidence of the pleiotropic role exerted on plant development by these oligosaccharins, and of the antagonism between auxin and OGs. Received: 4 March 1997 / Accepted: 15 July 1997     

Schistosoma mansoni: extramedullar eosinophil myelopoiesis induced by intraperitoneal glass implants in chronically infected mice

Intraperitoneal glass implants in mice with chronic Schistosoma mansoni infections induce intense local myeloid reactions involving essentially myeloid granulocytes. The same phenomenon is not observed in normal mice nor in mice with acute schistosomal infection. An association of myelopoiesis with differentiated macrophages mobilized on glass implants and with dense ameboid cells located inside myeloid foci was detected. A macrophage-dependent induction of this eosinophil reaction is postulated.