“Success in (Surviving) Bioscience and Pharmacology” – an eBook to improve the retention of diploma nurses transitioning to a Bachelor of Nursing course

Diploma students transitioning into the NS40 BNursing (BN) course at QUT withdraw from the bioscience and pharmacology units, and leave the university at higher rates than traditional students. The diploma students, entering in second year, have missed out on 2 units of bioscience taught to the traditional students in their first year, and miss out on a 3rd unit of bioscience taught to the traditional students in their 2nd year. Instead the diploma students receive one specialized unit in bioscience only i.e. a bridging unit. As a consequence, the diploma students may not have the depth of bioscience knowledge to be able to successfully study the bridging unit (LSB111) or the pharmacology unit (LSB384). Our plan was to write an eBook which refreshed and reinforced diploma students’ knowledge of bioscience aiming to prepare them with the concepts and terminology, and to build a level of confidence to support their transition to the BN. We have previously developed an intervention associated with reduced attrition of diploma nursing students, and this was our starting point. The study skills part of the initial intervention was addressed in the eBook, by links to the specialist services and resources available from our liaison librarian and academic skills adviser. The introductory bioscience/pharmacology information provided by the previous intervention involved material from standard textbooks. However, we considered this material too difficult for diploma students. Thus, we created simplified diagrams to go with text as part of our eBook. The outcome is an eBook, created and made available to the diploma students via the Community Website: “Surviving Bioscience and Pharmacology”. Using simplified diagrams to illustrate the concise text, definition to explain the concepts, the focus has been on encouraging self-awareness and help-seeking strategies and building students who take responsibility for their learning. All the nursing students in the second semester LSB384 Pharmacology Unit have been surveyed face-to-face to get feedback on their engagement with the eBook resource. The data has not been analysed to date. An important consideration is that the website be evaluated by the diploma students as they come into bioscience in first semester (LSB111), the student population for whom the eBook is primarily intended. To get a good response rate we need to do a face-to-face survey. However, we have not been able to do this, as the co-ordinator of the unit has changed since we started the project, and the present co-ordinator will not allow us access to these students.

Plasma biochemical responses of the planktivorous filter-feeding silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) to prolonged toxic cyanobacterial blooms in natural waters

The planktivorous filter-feeding silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) are the attractive candidates for bio-control of plankton communities to eliminate odorous populations of cyanobacteria. However, few studies focused on the health of such fishes in natural water body with vigorous toxic blooms. Blood parameters are useful and sensitive for diagnosis of diseases and monitoring of the physiological status of fish exposed to toxicants. To evaluate the impact of toxic cyanobacterial blooms on the planktivorous fish, 12 serum chemistry variables were investigated in silver carp and bighead carp for 9 months, in a large net cage in Meiliang Bay, a hypereutrophic region of Lake Taihu. The results confirmed adverse effects of cyanobacterial blooms on two phytoplanktivorous fish, which mainly characterized with potential toxicogenomic effects and metabolism disorders in liver, and kidney dysfunction. In addition, cholestasis was intensively implied by distinct elevation of all four related biomarkers (ALP, GGT, DBIL, TBIL) in bighead carp. The combination of LDH, AST activities and DBIL, URIC contents for silver carp, and the combination of ALT. ALP activities and TBIL, DBIL. URIC concentrations for bighead carps were found to most strongly indicate toxic effects from cyanobacterial blooms in such fishes by a multivariate discriminant analysis. (C) 2009 Elsevier B.V. All rights reserved.

Proprotein convertase subtilisin/kexin type 9 in human disease

Les maladies cardiovasculaires (MCV) demeurent au tournant de ce siècle la principale cause de mortalité dans le monde. Parmi les facteurs de risque, l’hypercholestérolémie et l’obésité abdominale sont directement liées au développement précoce de l’athérosclérose. L’hypercholestérolémie familiale, communément associée à une déficience des récepteurs des lipoprotéines de basse densité (LDLR), est connue comme cause de maladie précoce d’athérosclérose et de calcification aortique chez l’humain. La subtilisine convertase proprotéine/kexine du type 9 (PCSK9), membre de la famille des proprotéines convertases, est trouvée indirectement associée aux MCV par son implication dans la dégradation du LDLR. Chez l'humain, des mutations du gène PCSK9 conduisent soit à une hypercholestérolémie familiale, soit à une hypocholestérolémie, selon que la mutation entraîne un gain ou une perte de fonction, respectivement. Il demeure incertain si les individus porteurs de mutations causant un gain de fonction de la PCSK9 développeront une calcification aortique ou si des mutations entraînant une perte de fonction provoqueront une obésité abdominale. Dans cette étude, nous avons examiné : 1) l’effet d’une surexpression de PCSK9 dans le foie de souris sur la calcification aortique ; 2) les conséquences d’une déficience en PCSK9 (Pcsk9 KO), mimant une inhibition pharmacologique, sur le tissu graisseux. Nous avons utilisé un modèle de souris transgénique (Tg) surexprimant le cDNA de PCSK9 de souris dans les hépatocytes de souris et démontrons par tomographie calculée qu’une calcification survient de façon moins étendue chez les souris PCSK9 Tg que chez les souris déficientes en LDLR. Alors que le PCSK9 Tg et la déficience en LDLR causaient tous deux une hypercholestérolémie familiale, les niveaux seuls de cholestérol circulant ne parvenaient pas à prédire le degré de calcification aortique. Dans une seconde étude, nous utilisions des souris génétiquement manipulées dépourvues de PSCK9 et démontrons que l’accumulation de graisses viscérales (adipogenèse) apparaît régulée par la PCSK9 circulante. Ainsi, en l’absence de PCSK9, l’adipogenèse viscérale augmente vraisemblablement par régulation post-traductionnelle des récepteurs à lipoprotéines de très basse densité (VLDLR) dans le tissu adipeux. Ces deux modèles mettent en évidence un équilibre dynamique de la PCSK9 dans des voies métaboliques différentes, réalisant un élément clé dans la santé cardiovasculaire. Par conséquent, les essais d’investigations et d’altérations biologiques de la PCSK9 devraient être pris en compte dans un modèle animal valide utilisant une méthode sensible et en portant une attention prudente aux effets secondaires de toute intervention.

Factores asociados a fenómeno de no reflujo coronario en pacientes adultos llevados a angioplastia

Introducción: La disminución de flujo en los vasos coronarios sin presencia de oclusión, es conocido como fenómeno de no reflujo, se observa después de la reperfusión, su presentación oscila entre el 5% y el 50% dependiendo de la población y de los criterios diagnósticos, dicho suceso es de mal pronóstico, aumenta el riesgo de morir en los primeros 30 días posterior a la angioplastia (RR 2,1 p 0,038), y se relaciona con falla cardiaca y arritmias, por eso al identificar los factores a los cuales se asocia, se podrán implementar terapias preventivas. Metodología: Estudio de casos y controles pareado por médico que valoró el evento, para garantizar que no existieron variaciones inter observador, con una razón 1:4 (18:72), realizado para identificar factores asociados a la presencia de no reflujo en pacientes llevados a angioplastia, entre noviembre de 2010 y mayo de 2014, en la Clínica San Rafael de Bogotá, D.C. Resultados: La frecuencia del no reflujo fue del 2.89%. El Infarto Agudo de Miocardio con elevación del ST (IAMCEST) fue la única variable que mostró una asociación estadísticamente significativa con este suceso, valor de p 0,002, OR 8,7, IC 95% (2,0 – 36,7). Discusión: El fenómeno de no reflujo en esta población se comportó de manera similar a lo descrito en la literatura, siendo el IAMCEST un factor fuertemente asociado.

Role of alpha 7 Nicotinic Acetylcholine Receptor in Calcium Signaling Induced by Prion Protein Interaction with Stress-inducible Protein 1

The prion protein (PrP(C)) is a conserved glycosylphosphatidyl-inositol-anchored cell surface protein expressed by neurons and other cells. Stress-inducible protein 1 (STI1) binds PrP(C) extracellularly, and this activated signaling complex promotes neuronal differentiation and neuroprotection via the extracellular signal-regulated kinase 1 and 2 (ERK1/2) and cAMP-dependent protein kinase 1 (PKA) pathways. However, the mechanism by which the PrPC-STI1 interaction transduces extracellular signals to the intracellular environment is unknown. We found that in hippocampal neurons, STI1-PrP(C) engagement induces an increase in intracellular Ca(2+) levels. This effect was not detected in PrP(C)-null neurons or wild-type neurons treated with an STI1 mutant unable to bind PrP(C). Using a best candidate approach to test for potential channels involved in Ca(2+) influx evoked by STI1-PrP(C), we found that alpha-bungarotoxin, a specific inhibitor for alpha 7 nicotinic acetylcholine receptor (alpha 7nAChR), was able to block PrP(C)-STI1-mediated signaling, neuroprotection, and neuritogenesis. Importantly, when alpha 7nAChR was transfected into HEK 293 cells, it formed a functional complex with PrP(C) and allowed reconstitution of signaling by PrP(C)-STI1 interaction. These results indicate that STI1 can interact with the PrP(C).alpha 7nAChR complex to promote signaling and provide a novel potential target for modulation of the effects of prion protein in neurodegenerative diseases.

Melatonin and IP(3)-induced Ca(2+) Release from Intracellular Stores in the Malaria Parasite Plasmodium falciparum within Infected Red Blood Cells

IP(3)-dependent Ca(2+) signaling controls a myriad of cellular processes in higher eukaryotes and similar signaling pathways are evolutionarily conserved in Plasmodium, the intracellular parasite that causes malaria. We have reported that isolated, permeabilized Plasmodium chabaudi, releases Ca(2+) upon addition of exogenous IP(3). In the present study, we investigated whether the IP(3) signaling pathway operates in intact Plasmodium falciparum, the major disease-causing human malaria parasite. P. falciparum-infected red blood cells (RBCs) in the trophozoite stage were simultaneously loaded with the Ca(2+) indicator Fluo-4/AM and caged-IP(3). Photolytic release of IP(3) elicited a transient Ca(2+) increase in the cytosol of the intact parasite within the RBC. The intracellular Ca(2+) pools of the parasite were selectively discharged, using thapsigargin to deplete endoplasmic reticulum (ER) Ca(2+) and the antimalarial chloroquine to deplete Ca(2+) from acidocalcisomes. These data show that the ER is the major IP(3)-sensitive Ca(2+) store. Previous work has shown that the human host hormone melatonin regulates P. falciparum cell cycle via a Ca(2+)-dependent pathway. In the present study, we demonstrate that melatonin increases inositol-polyphosphate production in intact intraerythrocytic parasite. Moreover, the Ca(2+) responses to melatonin and uncaging of IP(3) were mutually exclusive in infected RBCs. Taken together these data provide evidence that melatonin activates PLC to generate IP(3) and open ER-localized IP(3)-sensitive Ca(2+) channels in P. falciparum. This receptor signaling pathway is likely to be involved in the regulation and synchronization of parasite cell cycle progression.

Leukotrienes Target F-actin/Cofilin-1 to Enhance Alveolar Macrophage Anti-fungal Activity

Candida albicans is the most common opportunistic fungal pathogen and causes local and systemic disease in immunocompromised patients. Alveolar macrophages (AMs) are pivotal for the clearance of C. albicans from the lung. Activated AMs secrete 5-lipoxygenase-derived leukotrienes (LTs), which in turn enhance phagocytosis and microbicidal activity against a diverse array of pathogens. Our aim was to investigate the role of LTB(4) and LTD(4) in AM antimicrobial functions against C. albicans and the signaling pathways involved. Pharmacologic and genetic inhibition of LT biosynthesis as well as receptor antagonism reduced phagocytosis of C. albicans when compared with untreated or WT controls. Conversely, exogenous LTs of both classes augmented base-line C. albicans phagocytosis by AMs. Although LTB(4) enhanced mainly mannose receptor-dependent fungal ingestion, LTD(4) enhanced mainly dectin-1 receptor-mediated phagocytosis. LT enhancement of yeast ingestion was dependent on protein kinase C-delta (PKC delta) and PI3K but not PKC alpha and MAPK activation. Both LTs reduced activation of cofilin-1, whereas they enhanced total cellular F-actin; however, LTB(4) accomplished this through the activation of LIM kinases (LIMKs) 1 and 2, whereas LTD(4) did so exclusively via LIMK-2. Finally, both exogenous LTB(4) and LTD(4) enhanced AM fungicidal activity in an NADPH oxidase-dependent manner. Our data identify LTB(4) and LTD(4) as key mediators of innate immunity against C. albicans, which act by both distinct and conserved signaling mechanisms to enhance multiple antimicrobial functions of AMs.

Alboserpin, a Factor Xa Inhibitor from the Mosquito Vector of Yellow Fever, Binds Heparin and Membrane Phospholipids and Exhibits Antithrombotic Activity

The molecular mechanism of factor Xa (FXa) inhibition by Alboserpin, the major salivary gland anticoagulant from the mosquito and yellow fever vector Aedes albopictus, has been characterized. cDNA of Alboserpin predicts a 45-kDa protein that belongs to the serpin family of protease inhibitors. Recombinant Alboserpin displays stoichiometric, competitive, reversible and tight binding to FXa (picomolar range). Binding is highly specific and is not detectable for FX, catalytic site-blocked FXa, thrombin, and 12 other enzymes. Alboserpin displays high affinity binding to heparin (K(D) similar to 20 nM), but no change in FXa inhibition was observed in the presence of the cofactor, implying that bridging mechanisms did not take place. Notably, Alboserpin was also found to interact with phosphatidylcholine and phosphatidylethanolamine but not with phosphatidylserine. Further, annexin V (in the absence of Ca(2+)) or heparin outcompetes Alboserpin for binding to phospholipid vesicles, suggesting a common binding site. Consistent with its activity, Alboserpin blocks prothrombinase activity and increases both prothrombin time and activated partial thromboplastin time in vitro or ex vivo. Furthermore, Alboserpin prevents thrombus formation provoked by ferric chloride injury of the carotid artery and increases bleeding in a dose-dependent manner. Alboserpin emerges as an atypical serpin that targets FXa and displays unique phospholipid specificity. It conceivably uses heparin and phosphatidylcholine/phosphatidylethanolamine as anchors to increase protein localization and effective concentration at sites of injury, cell activation, or inflammation.

Characterization of Gtf1p, the Connector Subunit of Yeast Mitochondrial tRNA-dependent Amidotransferase

The bacterial GatCAB operon for tRNA-dependent amidotransferase (AdT) catalyzes the transamidation of mischarged glutamyl-tRNA(Gln) to glutaminyl-tRNA(Gln). Here we describe the phenotype of temperature-sensitive (ts) mutants of GTF1, a gene proposed to code for subunit F of mitochondrial AdT in Saccharomyces cerevisiae. The ts gtf1 mutants accumulate an electrophoretic variant of the mitochondrially encoded Cox2p subunit of cytochrome oxidase and an unstable form of the Atp8p subunit of the F(1)-F(0) ATP synthase that is degraded, thereby preventing assembly of the F(0) sector. Allotopic expression of recoded ATP8 and COX2 did not significantly improve growth of gtf1 mutants on respiratory substrates. However, ts gft1 mutants are partially rescued by overexpression of PET112 and HER2 that code for the yeast homologues of the catalytic subunits of bacterial AdT. Additionally, B66, a her2 point mutant has a phenotype similar to that of gtf1 mutants. These results provide genetic support for the essentiality, in vivo, of the GatF subunit of the heterotrimeric AdT that catalyzes formation of glutaminyl-tRNA(Gln) (Frechin, M., Senger, B., Braye, M., Kern, D., Martin, R. P., and Becker, H. D. (2009) Genes Dev. 23, 1119-1130).