344 research outputs found
Clinical Manifestations and Case Management of Ebola Haemorrhagic Fever caused by a newly identified virus strain, Bundibugyo, Uganda, 2007-2008
A confirmed Ebola haemorrhagic fever (EHF) outbreak in Bundibugyo, Uganda, November 2007-February 2008, was caused by a putative new species (Bundibugyo ebolavirus). It included 93 putative cases, 56 laboratory-confirmed cases, and 37 deaths (CFR = 25%). Study objectives are to describe clinical manifestations and case management for 26 hospitalised laboratory-confirmed EHF patients. Clinical findings are congruous with previously reported EHF infections. The most frequently experienced symptoms were non-bloody diarrhoea (81%), severe headache (81%), and asthenia (77%). Seven patients reported or were observed with haemorrhagic symptoms, six of whom died. Ebola care remains difficult due to the resource-poor setting of outbreaks and the infection-control procedures required. However, quality data collection is essential to evaluate case definitions and therapeutic interventions, and needs improvement in future epidemics. Organizations usually involved in EHF case management have a particular responsibility in this respect
Stress-Induced Reinstatement of Drug Seeking: 20 Years of Progress
In human addicts, drug relapse and craving are often provoked by stress. Since 1995, this clinical scenario has been studied using a rat model of stress-induced reinstatement of drug seeking. Here, we first discuss the generality of stress-induced reinstatement to different drugs of abuse, different stressors, and different behavioral procedures. We also discuss neuropharmacological mechanisms, and brain areas and circuits controlling stress-induced reinstatement of drug seeking. We conclude by discussing results from translational human laboratory studies and clinical trials that were inspired by results from rat studies on stress-induced reinstatement. Our main conclusions are (1) The phenomenon of stress-induced reinstatement, first shown with an intermittent footshock stressor in rats trained to self-administer heroin, generalizes to other abused drugs, including cocaine, methamphetamine, nicotine, and alcohol, and is also observed in the conditioned place preference model in rats and mice. This phenomenon, however, is stressor specific and not all stressors induce reinstatement of drug seeking. (2) Neuropharmacological studies indicate the involvement of corticotropin-releasing factor (CRF), noradrenaline, dopamine, glutamate, kappa/dynorphin, and several other peptide and neurotransmitter systems in stress-induced reinstatement. Neuropharmacology and circuitry studies indicate the involvement of CRF and noradrenaline transmission in bed nucleus of stria terminalis and central amygdala, and dopamine, CRF, kappa/dynorphin, and glutamate transmission in other components of the mesocorticolimbic dopamine system (ventral tegmental area, medial prefrontal cortex, orbitofrontal cortex, and nucleus accumbens). (3) Translational human laboratory studies and a recent clinical trial study show the efficacy of alpha-2 adrenoceptor agonists in decreasing stress-induced drug craving and stress-induced initial heroin lapse
The Global Research Neglect of Unassisted Smoking Cessation: Causes and Consequences
Simon Chapman and Ross MacKenzie review the evidence and argue that health promotion messages should emphasize that the most successful method used by most ex-smokers is unassisted cessation
Smoking onset and the time-varying effects of self-efficacy, environmental smoking, and smoking-specific parenting by using discrete-time survival analysis
This study examined the timing of smoking onset during mid- or late adolescence and the time-varying effects of refusal self-efficacy, parental and sibling smoking behavior, smoking behavior of friends and best friend, and parental smoking-specific communication. We used data from five annual waves of the ‘Family and Health’ project. In total, 428 adolescents and their parents participated at baseline. Only never smokers were included at baseline (n = 272). A life table and Kaplan–Meier survival curve showed that 51% of all adolescents who did not smoke at baseline did not start smoking within 4 years. The risk for smoking onset during mid- or late adolescence is rather stable (hazard ratio between 16 and 19). Discrete-time survival analyses revealed that low refusal self-efficacy, high frequency of communication, and sibling smoking were associated with smoking onset one year later. No interaction effects were found. Conclusively, the findings revealed that refusal self-efficacy is an important predictor of smoking onset during mid- or late adolescence and is independent of smoking-specific communication and smoking behavior of parents, siblings, and (best) friend(s). Findings emphasize the importance of family prevention programs focusing on self-efficacy skills
Does smoking among friends explain apparent genetic effects on current smoking in adolescence and young adulthood?
We used data from a prospective cohort study of twins to investigate the influence of unmeasured genetic and measured and unmeasured environmental factors on the smoking behaviour of adolescents and young adults. Twins were surveyed in 1988 (aged 11–18 years), 1991, 1996 and 2004 with data from 1409, 1121, 732 and 758 pairs analysed from each survey wave, respectively. Questionnaires assessed the smoking behaviour of twins and the perceived smoking behaviour of friends and parents. Using a novel logistic regression analysis, we simultaneously modelled individual risk and excess concordance for current smoking as a function of zygosity, survey wave, parental smoking and peer smoking. Being concordant for having peers who smoked was a predictor of concordance for current smoking (P<0.001). After adjusting for peer smoking, monozygotic (MZ) pairs were no more alike than dizygotic pairs for current smoking at waves 2, 3 and 4. Genetic explanations are not needed to explain the greater concordance for current smoking among adult MZ pairs. However, if they are invoked, the role of genes may be due to indirect effects acting through the social environment. Smoking prevention efforts may benefit more by targeting social factors than attempting to identify genetic factors associated with smoking
Using Genomic Sequencing for Classical Genetics in E. coli K12
We here develop computational methods to facilitate use of 454 whole genome shotgun sequencing to identify mutations in Escherichia coli K12. We had Roche sequence eight related strains derived as spontaneous mutants in a background without a whole genome sequence. They provided difference tables based on assembling each genome to reference strain E. coli MG1655 (NC_000913). Due to the evolutionary distance to MG1655, these contained a large number of both false negatives and positives. By manual analysis of the dataset, we detected all the known mutations (24 at nine locations) and identified and genetically confirmed new mutations necessary and sufficient for the phenotypes we had selected in four strains. We then had Roche assemble contigs de novo, which we further assembled to full-length pseudomolecules based on synteny with MG1655. This hybrid method facilitated detection of insertion mutations and allowed annotation from MG1655. After removing one genome with less than the optimal 20- to 30-fold sequence coverage, we identified 544 putative polymorphisms that included all of the known and selected mutations apart from insertions. Finally, we detected seven new mutations in a total of only 41 candidates by comparing single genomes to composite data for the remaining six and using a ranking system to penalize homopolymer sequencing and misassembly errors. An additional benefit of the analysis is a table of differences between MG1655 and a physiologically robust E. coli wild-type strain NCM3722. Both projects were greatly facilitated by use of comparative genomics tools in the CoGe software package (http://genomevolution.org/)
Hydrokinetic Turbine Effects on Fish Swimming Behaviour
Hydrokinetic turbines, targeting the kinetic energy of fast-flowing currents, are under development with some turbines
already deployed at ocean sites around the world. It remains virtually unknown as to how these technologies affect
fish, and rotor collisions have been postulated as a major concern. In this study the effects of a vertical axis
hydrokinetic rotor with rotational speeds up to 70 rpm were tested on the swimming patterns of naturally occurring
fish in a subtropical tidal channel. Fish movements were recorded with and without the rotor in place. Results showed
that no fish collided with the rotor and only a few specimens passed through rotor blades. Overall, fish reduced their
movements through the area when the rotor was present. This deterrent effect on fish increased with current speed.
Fish that passed the rotor avoided the near-field, about 0.3 m from the rotor for benthic reef fish. Large predatory fish
were particularly cautious of the rotor and never moved closer than 1.7 m in current speeds above 0.6 ms-1. The
effects of the rotor differed among taxa and feeding guilds and it is suggested that fish boldness and body shape
influenced responses. In conclusion, the tested hydrokinetic turbine rotor proved non-hazardous to fish during the
investigated conditions. However, the results indicate that arrays comprising multiple turbines may restrict fish
movements, particularly for large species, with possible effects on habitat connectivity if migration routes are
exploited. Arrays of the investigated turbine type and comparable systems should therefore be designed with gaps of
several metres width to allow large fish to pass through. In combination with further research the insights from this
study can be used for guiding the design of hydrokinetic turbine arrays where needed, so preventing ecological
impacts
Becoming the best mom that I can: women's experiences of managing depression during pregnancy – a qualitative study
<p>Abstract</p> <p>Background</p> <p>The purpose of this constructivist grounded theory study was to develop a theoretical model that explains women's processes of managing diagnosed depression when pregnant.</p> <p>Methods</p> <p>We explored the experiences of 19 women in Ontario who were diagnosed with depression during their pregnancy.</p> <p>Results</p> <p>The model that emerged from the analysis was becoming the best mom that I can. Becoming the best mom that I can explains the complex process of the women's journey as they travel from the depths of despair, where the depression is perceived to threaten their pregnancy and their ability to care for the coming baby, to arrive at knowing the self and being in a better place. In order to reground the self and regain control of their lives, the women had to recognize the problem, overcome shame and embarrassment, identify an understanding healthcare provider, and consider the consequences of the depression and its management. When confronting and confining the threat of depression, the women employed strategies of overcoming barriers, gaining knowledge, and taking control. As a result of counseling, medication, or a combination of both, women felt that they had arrived at a better place.</p> <p>Conclusion</p> <p>For many women, the idea that depression could occur during pregnancy was antithetical to their vision of the pregnant self. The challenge for a pregnant woman who is diagnosed with depression, is that effective care for her may jeopardize her baby's future health. This provides a dilemma for about-to-be parents and their healthcare providers. Improved awareness of depression during pregnancy on the part of healthcare professionals is needed to improve the women's understanding of this disorder and their ability to recognize and seek help with depression should it occur during the prenatal period. Further qualitative research is needed to determine the specific aspects that need to be addressed in such classes.</p
Globally prevalent PfMDR1 mutations modulate Plasmodium falciparum susceptibility to artemisinin-based combination therapies
Antimalarial chemotherapy, globally reliant on artemisinin-based combination therapies (ACTs), is threatened by the spread of drug resistance in Plasmodium falciparum parasites. Here we use zinc-finger nucleases to genetically modify the multidrug resistance-1 transporter PfMDR1 at amino acids 86 and 184, and demonstrate that the widely prevalent N86Y mutation augments resistance to the ACT partner drug amodiaquine and the former first-line agent chloroquine. In contrast, N86Y increases parasite susceptibility to the partner drugs lumefantrine and mefloquine, and the active artemisinin metabolite dihydroartemisinin. The PfMDR1 N86 plus Y184F isoform moderately reduces piperaquine potency in strains expressing an Asian/African variant of the chloroquine resistance transporter PfCRT. Mutations in both digestive vacuole-resident transporters are thought to differentially regulate ACT drug interactions with host haem, a product of parasite-mediated haemoglobin degradation. Global mapping of these mutations illustrates where the different ACTs could be selectively deployed to optimize treatment based on regional differences in PfMDR1 haplotypes.This work was funded in part by the National Institutes of Health (R01 AI50234, AI124678 and AI109023) and a Burroughs Wellcome Fund Investigator in Pathogenesis of Infectious Diseases award to D.A.F. This research also received funding from the Portuguese Fundacao para a Ciencia e Tecnologia (FCT), cofunded by Programa Operacional Regional do Norte (ON.2-O Novo Norte); from the Quadro de Referencia Estrategico Nacional (QREN) through the Fundo Europeu de Desenvolvimento Regional (FEDER) and from the Projeto Estrategico - LA 26 - 2013-2014 (PEst-C/SAU/LA0026/2013). M.I.V. is the recipient of a postdoctoral fellowship from FCT/Ministerio da Ciencia e Ensino Superior, Portugal-MCES (SFRH/BPD/76614/2011). A.M.L. was supported by an Australian National Health and Medical Research Council (NHMRC) Overseas Biomedical Fellowship (585519). R.E.M. was supported by an NHMRC RD Wright Biomedical Fellowship (1053082). A.C.U. was supported by an Irving scholarship from Columbia University. We thank Dr Andrea Ecker for her help with plasmid design and Pedro Ferreira for his expert help with Fig. 6.info:eu-repo/semantics/publishedVersio
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