Developing the ethics of implementation research in health

Implementation research (IR) is growing in recognition as an important generator of practical knowledge that can be translated into health policy. With its aim to answer questions about how to improve access to interventions that have been shown to work but have not reached many of the people who could benefit from them, IR involves a range of particular ethical considerations that have not yet been comprehensively covered in international guidelines on health research ethics. The fundamental ethical principles governing clinical research apply equally in IR, but the application of these principles may differ depending on the IR question, context, and the nature of the proposed intervention. IR questions cover a broad range of topics that focus on improving health system functioning and improving equitable and just access to effective health care interventions. As such, IR designs are flexible and often innovative, and ethical principles cannot simply be extrapolated from their applications in clinical research. Meaningful engagement with all stakeholders including communities and research participants is a fundamental ethical requirement that cuts across all study phases of IR and links most ethical concerns. Careful modification of the informed consent process may be required in IR to permit study of a needed intervention. The risks associated with IR may be difficult to anticipate and may be very context-specific. The benefits of IR may not accrue to the same groups who participate in the research, therefore justifying the risks versus benefits of IR may be ethically challenging. The expectation that knowledge generated through IR should be rapidly translated into health policy and practice necessitates up-front commitments from decision-makers to sustainability and scalability of effective interventions. Greater awareness of the particular ethical implications of the features of IR is urgently needed to facilitate optimal ethical conduct of IR and uniform ethical review.     

The genus Eodasycladus (Lower Jurassic dasycladalean green alga) and its relationship with Palaeodasycladus

The Lower Jurassic genus Eodasycladus is discussed according to the characters of type species and compared with the other species known in the literature. The architecture of two species attributed to the genus Palaeodasycladus, P. alanensis Soka?, and P. benceki Soka?, is examined and an alternative organization of the thallus is prospected. P. alanensis is considered a valid species, but its characters require to transfer the taxon to the genus Eodasycladus. P. benceki is considered synonymous with P. alanensis.     

Analyses of Arabidopsis trr14 T-DNA Insertion Mutants Reveal an Essential Role in Seed Germination

TRR14 is an unknown protein that was first identified as a component of Arabidopsis responses to trehalose treatment. Phylogenic analysis showed that TRR14 belongs to a seven-gene family in Arabidopsis. Close homologues of TRR14 were found in plants and many cyanobacteria. GFP expression analysis showed that TRR14 is located in the chloroplast. GUS::TRR14 expression was found in leaves, flowers, stems and siliques. We investigated the functional roles of TRR14 in Arabidopsis thaliana under salt and drought stress. By a reverse genetic approach, two trr14 T-DNA insertion mutants were isolated from the SALK collection. Functional analysis of the trr14 mutants revealed enhanced sensitivity of the mutants to salt and drought stress, compared with the wild type plants. Further experiments indicated that the trr14 mutants have reduced seed germination, root length, survival rate and chlorophyll content under stress conditions. In addition activity of oxidative enzymes like peroxidase, catalase and polyphenol oxidase was reduced under salt and drought treatments. Thus, the present data indicate that a novel protein, TRR14, is involved in plant salt and drought tolerance.     

Estrogen prevents cardiomyocyte apoptosis through inhibition of reactive oxygen species and differential regulation of p38 kinase isoforms

From human and animal studies, estrogen is known to protect the myocardium from an ischemic insult. However, there is limited knowledge regarding mechanisms by which estrogen directly protects cardiomyocytes. In this report, we employed an in vitro model, in which cultured rat cardiomyocytes underwent prolonged hypoxia followed by reoxygenation (H/R), to study the cardioprotective mechanism of estrogen. 17-beta-estradiol (E2) acting via estrogen receptors inhibited H/R-induced apoptosis of cardiomyocytes. Mitochondrial reactive oxygen species (ROS) generated from H/R activated p38alpha MAPK, and inhibition of p38alpha with SB203580 significantly prevented H/R-induced cell death. E2 suppressed ROS formation and p38alpha activation by H/R and concomitantly augmented the activity of p38beta. Unlike p38alpha, p38beta was little affected by H/R. Dominant negative p38beta protein expression decreased E2-mediated cardiomyocyte survival and ROS suppression during H/R stress. The prosurvival signaling molecule, phosphoinositol-3 kinase (PI3K), has previously been linked to cell survival following ischemia-reperfusion injury. Here, E2-activated PI3K was found to inhibit ROS generated from H/R injury, leading to inhibition of downstream p38alpha. We further linked these signaling pathways in that p38beta was activated by E2 stimulation of PI3K. Thus, E2 differentially modulated two major isoforms of p38, leading to cardiomyocyte survival. This was achieved by signaling through PI3K, integrating cell survival mediators.     

Phosphorylation of Collapsin Response Mediator Protein 2 on Tyr-479 Regulates CXCL12-induced T Lymphocyte Migration

In the central nervous system, collapsin response mediator protein 2 (CRMP2) is a transducer protein that supports the semaphorin-induced guidance of axons toward their cognate target. However, we previously showed that CRMP2 is also expressed in immune cells and plays a crucial role in T lymphocyte migration. Here we further investigated the molecular mechanisms underlying CRMP2 function in chemokine-directed T-cell motility. Examining Jurkat T-cells treated with the chemokine CXCL12, we found that 1) CXCL12 induces a dynamic re-localization of CRMP2 to uropod, the flexible structure of migrating lymphocyte, and increases its binding to the cytoskeletal protein vimentin; 2) CXCL12 decreases phosphorylation of the glycogen synthase kinase-3β-targeted residues CRMP2-Thr-509/514; and 3) tyrosine Tyr-479 is a new phosphorylation CRMP2 residue and a target for the Src-family kinase Yes. Moreover, phospho-Tyr-479 increased under CXCL12 signaling while phospho-Thr-509/514 decreased. The functional importance of this tyrosine phosphorylation was demonstrated by Y479F mutation that strongly reduced CXCL12-mediated T-cell polarization and motility as tested in a transmigration model and on neural tissue. We propose that differential phosphorylation by glycogen synthase kinase-3β and Yes modulates the contribution of CRMP2 to cytoskeletal reorganization during chemokine-directed T-cell migration. In addition to providing a novel mechanism for T lymphocyte motility, our findings reveal CRMP2 as a transducer of chemokine signaling.T lymphocyte migration is the basis of major immune functions such as responses to infection and inflammation, as well as normal recirculation through the lymphoid organs. Indeed, the role of T-cells depends strongly on their ability to travel between organs via the blood and lymph and to move rapidly within these tissues, by extravasation (1). This latter function is dependent on extracellular signals, among which chemokines play a major role.Chemokines form a superfamily of small proteins that orchestrate lymphocyte polarization and migration (2). These proteins exert their functions by binding specific seven-transmembrane-domain G-protein-coupled receptors on the T-cell surface (3). T-lymphocytes exposed to chemokines, in a soluble or surface-bound gradient, develop a polarized shape, extending at the front, an F-actin-rich lamellipodium, which constitutes the leading edge, and a trailing edge or uropod in which both the microtubule and vimentin networks are retracted during migration. Although F-actin has the well known function of producing the mechanical forces required to generate movement (4), the role of microtubules and vimentin in T-cell migration requires further investigation.Cytoskeletal remodeling is of key importance in migrating cells (5) and is one of the functions carried out by the chemokine stromal cell-derived factor-1α, also named CXCL12. In association with its cognate receptor CXCR4, CXCL12 is a potent chemoattractant for mature T-cells and monocytes (6). Following ligand recognition and binding, CXCR4 signaling starts with the activation of G proteins, followed by various signaling cascade effectors, including MAP² kinases, phosphoinositide 3-kinase, and phospholipase Cγ (7). Although this intracellular signaling cascade has not been completely elucidated, the Src family non-receptor tyrosine kinase Lck and the Syk kinase ZAP-70 have emerged as the main candidates for delivering the input signal following CXCR4 activation (8). Thus, tyrosine kinase activity appears as a central step in CXCR4-dependent chemotaxis.While searching for molecules involved in T-cell motility, we recently identified collapsin response mediator protein 2 (CRMP2) (9), a protein first described in the context of neuronal growth cone advance (10, 11). We demonstrated that CRMP2 regulated both T-cell polarization and spontaneous/chemokine-induced migration of T-lymphocytes. Moreover, CRMP2 was found at the uropod of motile T-cells and has the ability to bind cytoskeletal elements, including vimentin. A correlation between CRMP2 expression levels and cell migratory rates toward a chemokine gradient, including CXCL12, was demonstrated by overexpression and knockdown experiments in T-cells (9). In addition, we recently reported that, in mouse model of neuroinflammation, elevated CRMP2 expression in T lymphocytes correlated with their elevated migratory rates and their ability to target the central nervous system (12). The importance of CXCL12 in the central nervous system and its implication in the pathogenesis of central nervous system disorders, including neuroinflammatory diseases, are well documented (review in Ref. 13). Thus, the aim of the present study was to determine whether and how CRMP2 participates in the transduction pathway induced by CXCL12 on T lymphocytes.     

Evaluation of oil recovery by rhamnolipid produced with isolated strain from Iranian oil wells

A rhamnolipid producing bacterium,Pseudomonas aeruginosa HR was isolated from south of Iranian oil wells. In the previous study, effects of main factors of cultivation on production of biosurfactant by this strain were evaluated and their optimized values were determined. In the present paper, the ability of produced biosurfactant in oil recovery was investigated. For this purpose, its affect on enhanced oil recovery in sand pack and core holder obtained from oil wells was evaluated. It was found that the maximum oil recovery in saturated sand pack column and in saturated core holder of crude oil were 23.6 and 64%, respectively. Then, in core test mathematical model was proposed by considering interactions between given parameters. Furthermore, dependence of residual oil recovery on the process of core washing during injection of biosurfactant was investigated. Finally, capillary desaturation curve was compared with core flood data.     

Functional estrogen receptors in the mitochondria of breast cancer cells

Steroid hormones have been reported to indirectly impact mitochondrial functions, attributed to nuclear receptor-induced production of proteins that localize in this cytoplasmic organelle. Here we show high-affinity estrogen receptors in the mitochondria of MCF-7 breast cancer cells and endothelial cells, compatible with classical estrogen receptors ERalpha and ERbeta. We report that in MCF-7, estrogen inhibits UV radiation-induced cytochrome C release, the decrease of the mitochondrial membrane potential, and apoptotic cell death. UV stimulated the formation of mitochondrial reactive oxygen species (mROS), and mROS were essential to inducing mitochondrial events of cell death. mROS mediated the UV activation of c-jun N-terminal kinase (JNK), and protein kinase C (PKC) delta, underlying the subsequent translocation of Bax to the mitochondria where oligomerization was promoted. E2 (estradiol) inhibited all these events, directly acting in mitochondria to inhibit mROS by rapidly up-regulating manganese superoxide dismutase activity. We implicate novel functions of ER in the mitochondria of breast cancer that lead to the survival of the tumor cells.     

Developmental changes in Drosophila melanogaster following exposure to alternating electromagnetic fields

This study investigated the biological effects of alternating electromagnetic fields (EMFs) on developmental stages of Drosophila melanogaster eggs and the first, second and third instar larvae stages. D. melanogaster eggs and larval stages were exposed to a 11 mT 50 Hz field produced by a pair of Helmholtz coils. Each stage was exposed to aEMFs for 2, 4, 6 and 8 h. Features of adult flies such as head, thorax, abdomen and other morphological changes were studied and compared. The frequency of abnormal flies was calculated using statistical methods at P <.05. The results obtained from exposing larvae in different stages of development showed a significant increase in the number of abnormal adult flies, whereas no significant increase was observed in the group arising from eggs exposed to aEMFs. Also, it appeared that duration of exposure correlates with the increase in the number of abnormal flies. There was no significant difference in mortality rate and sex distribution of the abnormal flies between field exposed and the control groups.     

Dynamic quantification of the tyrosine phosphorylation of the sperm surface proteins during capacitation.

BACKGROUND: Spermatozoa acquire active fertilizing competence only after deposition in the female tract and subsequent capacitation. Recent studies on the cellular location of major sperm phosphoproteins suggest that capacitation is associated with tyrosine phosphorylation of proteins exposed on the sperm surface. However, these changes have not yet been quantified objectively. A calcium influx seems to be required for the completion of tyrosine phosphorylation in some species; however, the exact temporal coordination between these processes is still poorly understood. METHODS: Flow cytometry was used to quantify the degree of phosphorylation of the sperm surface proteins by probing with fluorescein isothiocyanate-conjugated anti-phosphotyrosine (pY) antibody raised in mouse. Dynamic changes in other sperm parameters (calcium influx, membrane integrity, and spontaneous acrosome reaction) were assessed to analyze their temporal coordination. RESULTS:: The changes in specific phosphotyrosine (pY) fluorescence signal detected in live, nonpermeabilized boar cell suspensions were biphasic during incubation under capacitating conditions. After 120 min of incubation, the degree of pY fluorescence increased threefold, indicating the changes in proteins exposed on sperm surface. At the same time there was a gradual increase in cytosolic calcium ion levels with the maximal rate at 60 min of incubation. This rate slowed immediately before the onset of the massive rise in tyrosine phosphorylation and decreased by 90% after its completion. The integrity of plasma and acrosome membranes decreased only slowly, illustrating that the changes observed were not due to the process of spontaneous acrosome reaction. CONCLUSIONS: These data provide quantitative evidence for the appearance of tyrosine-phosphorylated proteins on the surface of live boar spermatozoa during capacitation. An exact temporal coordination exists between cytosolic calcium ion content and protein tyrosine phosphorylation under these conditions. This novel approach has the advantage of making possible a precise quantification and kinetic comparison of molecular processes in different cell subpopulations.