Interpretive Phenomenological Analysis: Exploring the Experiences of Eye Bank Coordinators When Approaching Families of Decedents for Eye Donation

This dissertation was used to addresses a group of individuals who work as eye bank coordinators. These individuals call families and approach them for eye donations from a loved one who has just passed away. An interpretative phenomenological analysis (IPA) was used to explain the lived experience of eye bank coordinators who call families for consent of eye tissue. The focus was to understand the dedication of the coordinators to giving the gift of sight and exploring the positive and negative experiences of eye bank coordinators. IPA is used for a keen understanding of eye bank coordinators, and the investigator gained insight as to why their role and well-being is important to eye banks by conducting and analyzing the interviews through the lived experiences of eye bank coordinators. The theoretical underpinnings of this research were based on the theory of planned behavior and self-perception theory. Four participants were interviewed as to their positive and negative experiences in their daily work. The research questions were What are the positive and negative experiences of eye bank coordinators when requesting permission for eye donations from bereaved families (RQ1)? and How do the positive and negative lived experience of eye bank coordinators influence their adjustment of strategies when requesting permission for eye donations from bereaved families (RQ2)? Encountering positive and enthusiastic family donors, needing to understand the situation or grief of family members, encountering closed-minded family members, and limited negative encounters experienced were the main themes that addressed RQ1. The main themes that addressed RQ2 were having the energy and motivation to seek for more donors, ensuring the right information was conveyed to the families, feeling more relaxed and comfortable, continuing to explain and ensure the correct information was conveyed, coaching and collecting oneself back, knowing how to read the actions and reactions of families, and learning from experiences and becoming more cautious

Lyt-2 glycoprotein is synthesized as a single molecular species

We investigated the possibility that the Lyt-2 molecules made by uncloned mouse T lymphocytes would show variable primary structures like those of immunoglobulins. Newly synthesized Lyt-2/3 complexes were found to include only two major components, both discrete glycoproteins with apparent molecular weights of 31,000 (31 K) and 35,000 (35 K). When products of Lyt-2.1 and Lyt-2.2 thymocytes were compared by two-dimensional nonequilibrium pH gradient electrophoresis and sodium dodecyl sulfate polyacrylamide gel electrophoresis, the isoelectric points of the 35 K molecules were different; thus, the 35 K component was likely to be encoded by the Lyt-2 locus itself. However, the 35 K molecules made by any one genotype were homogeneous in charge as well as in size. The homogeneity was obscured rapidly by post-translational modification. Most strikingly, within 30 min of initial synthesis, these processing events generated the conspicuous array of microheterogeneous products that form the "38 K" component of cell-surface Lyt-2/3

A finer print than TADs: PRC1-mediated domains

Polycomb proteins are well-known epigenetic repressors with unexplained roles in chromatin folding. In this issue of Molecular Cell, Kundu et al. (2017) investigate the structures of PRC1-mediated domains in stem cells and probe their changes upon differentiation and in PRC knockouts

Keep them close: PRC2 poises enhancer-promoter interactions at anterior neuronal genes

Enhancers exist in different epigenetic states: active, primed, or poised. However, it is not yet understood how the different enhancer states influence gene activation. In this issue of Cell Stem Cell, Cruz-Molina et al. (2017) unravel how poised enhancers activate anterior neural genes and the role of Polycomb proteins in enhancer-promoter contacts

Ossifying fibroma of the middle turbinate revealed by infection in a young child

SummaryIntroductionOssifying fibroma (OF) is a rare benign fibro-osseous tumor, mainly located in the head and neck region. Most often, it affects the mandible but rare involvement of paranasal sinuses has been reported, associated with more locally aggressive behavior.Case reportWe report the case of an 8-year-old boy with OF of the middle turbinate, revealed by ethmoiditis. Total resection was performed on an endoscopic approach. The patient was free of clinical or radiological recurrence at 3 years’ follow-up. This was the youngest patient with OF of the middle turbinate so far reported in the international literature.DiscussionPresumptive diagnosis is established by clinical examination and CT scan (location, oval-shaped mass, heterogeneous tumor with a thin bony rim). Definitive diagnosis is founded on histological examination (psammomatous bodies, osteoblastic rim, trabecular bone). Treatment in paranasal sinus OF is surgical, preferentially on an endoscopic approach. Resection should be as complete as possible to minimize risk of recurrence, especially in sinonasal locations, known to be more aggressive. Ethmoiditis in an unusual age-range should suggest tumoral etiology

Reticulocyte binding protein homologues are key adhesins during erythrocyte invasion by Plasmodium falciparum

The Apicomplexan parasite responsible for the most virulent form of malaria, Plasmodium falciparum, invades human erythrocytes through multiple ligand–receptor interactions. The P. falciparum reticulocyte-binding protein homologue (PfRh or PfRBL) family have been implicated in the invasion process but their exact role is unknown. PfRh1 and PfRh4, members of this protein family, bind to red blood cells and function in merozoite invasion during which they undergo a series of proteolytic cleavage events before and during entry into the host cell. The ectodomain of PfRh1 and PfRh4 are processed to produce fragments consistent with cleavage in the transmembrane domain and released into the supernatant, at about the time of invasion, in a manner consistent with rhomboid protease cleavage. Processing of both PfRh1 and PfRh4, and by extrapolation all membrane-bound members of this protein family, is important for function and release of these proteins on the merozoite surface and they along with EBA-175 are important components of the tight junction, the transient structure that links the erythrocyte via receptor–ligand interactions to the actin–myosin motor in the invading merozoite

Guanylyl cyclase activity associated with putative bifunctional integral membrane proteins in Plasmodium falciparum.

We report here that guanylyl cyclase activity is associated with two large integral membrane proteins (PfGCalpha and PfGCbeta) in the human malaria parasite Plasmodium falciparum. Unusually, the proteins appear to be bifunctional; their amino-terminal regions have strong similarity with P-type ATPases, and the sequence and structure of the carboxyl-terminal regions conform to that of G protein-dependent adenylyl cyclases, with two sets of six transmembrane sequences, each followed by a catalytic domain (C1 and C2). However, amino acids that are enzymatically important and present in the C2 domain of mammalian adenylyl cyclases are located in the C1 domain of the P. falciparum proteins and vice versa. In addition, certain key residues in these domains are more characteristic of guanylyl cyclases. Consistent with this, guanylyl cyclase activity was obtained following expression of the catalytic domains of PfGCbeta in Escherichia coli. In P. falciparum, expression of both genes was detectable in the sexual but not the asexual blood stages of the life cycle, and PfGCalpha was localized to the parasite/parasitophorous vacuole membrane region of gametocytes. The profound structural differences identified between mammalian and parasite guanylyl cyclases suggest that aspects of this signaling pathway may be mechanistically distinct

An atypical orthologue of 6-pyruvoyltetrahydropterin synthase can provide the missing link in the folate biosynthesis pathway of malaria parasites

Folate metabolism in malaria parasites is a long-standing, clinical target for chemotherapy and prophylaxis. However, despite determination of the complete genome sequence of the lethal species Plasmodium falciparum, the pathway of de novo folate biosynthesis remains incomplete, as no candidate gene for dihydroneopterin aldolase (DHNA) could be identified. This enzyme catalyses the third step in the well-characterized pathway of plants, bacteria, and those eukaryotic microorganisms capable of synthesizing their own folate. Utilizing bioinformatics searches based on both primary and higher protein structures, together with biochemical assays, we demonstrate that P. falciparum cell extracts lack detectable DHNA activity, but that the parasite possesses an unusual orthologue of 6-pyruvoyltetrahydropterin synthase (PTPS), which simultaneously gives rise to two products in comparable amounts, the predominant of which is 6-hydroxymethyl-7,8-dihydropterin, the substrate for the fourth step in folate biosynthesis (catalysed by 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase; PPPK). This can provide a bypass for the missing DHNA activity and thus a means of completing the biosynthetic pathway from GTP to dihydrofolate. Supported by site-directed mutagenesis experiments, we ascribe the novel catalytic activity of the malarial PTPS to a Cys to Glu change at its active site relative to all previously characterized PTPS molecules, including that of the human host

Dynamic changes in cytoskeleton proteins of olfactory ensheathing cells induced by radiofrequency electromagnetic fields.

Several evidences have suggested the ability of radio frequency electromagnetic fields to influence biological systems, even if the action mechanisms are not well understood. Only few data have reported about the effect of radio frequency electromagnetic fields on self-renewal of neural progenitor cells. A particular glial type, which shows characteristics of stem cells, are Olfactory Ensheathing Cells (OECs). Herein, we assessed the non-thermal effects induced on Olfactory Ensheathing Cells through radio frequency electromagnetic fields changing the envelope of the electromagnetic wave. Primary OEC cultures were exposed to continuous or amplitude modulated 900 MHz electromagnetic fields, in far field condition and at different exposition times (10, 15, 20 min). The expression of Olfactory Ensheathing Cells markers (S-100 and Nestin), cytoskeletal proteins (GFAP and Vimentin), apoptotic pathway activation by Caspase-3 cleavage and cell viability were evaluated. Our results highlight that 20 min of exposure to continuous or amplitude modulated 900 MHz electromagnetic fields induced a different and significant decrease in cell viability. In addition, according to the electromagnetic fields waveform, diverse dynamic changes in the expression of the analysed markers in Olfactory Ensheathing Cells and activation of apoptotic pathway were observed. The data suggest that radio frequency electromagnetic fields might play different and important role in the self-renewal of OEC stem cells, which are involved in nervous system repair