643 research outputs found

    Low prevalence of hepatitis C co-infection in recently HIV-infected minority men who have sex with men in Los Angeles: a cross-sectional study.

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    BackgroundGeographic and sociodemographic characterization of hepatitis C virus (HCV) transmission amongst men who have sex with men (MSM) has been limited. Our aim was to characterize HCV prevalence, risk factors for HCV co-infection, and patterns of HIV and HCV co-transmission and transmitted drug resistance mutations (DRMs) in newly HIV-diagnosed Los Angeles MSM.MethodsViral RNA was extracted from stored plasma samples from a Los Angeles cohort of newly diagnosed HIV-infected MSM with well-characterized substance use and sexual behavioral characteristics via computer-assisted self-interviewing surveys. Samples were screened for HCV by qPCR. HCV E1, E2, core, NS3 protease and NS5B polymerase and HIV-1 protease and reverse transcriptase regions were amplified and sequenced. Phylogenetic analysis was used to determine relatedness of HCV and HIV-1 isolates within the cohort and viral sequences were examined for DRMs.ResultsOf 185 newly HIV-diagnosed MSM, the majority (65%) were of minority race/ethnicity and recently infected (57.8%), with median age of 28.3 years. A minority (6.6%) reported injection drug use (IDU), whereas 96 (52.8%) reported recent substance use, primarily cannabis or stimulant use. High risk sexual behaviors included 132 (74.6%) with unprotected receptive anal intercourse, 60 (33.3%) with group sex, and 10 (5.7%) with fisting. Forty-five (24.3%) had acute gonorrhea or chlamydia infection. Only 3 (1.6%) subjects had detectable HCV RNA. Amongst these subjects, HIV and HCV isolates were unrelated by phylogenetic analysis and none possessed clinically relevant NS3 or NS5B HCV DRMs.ConclusionsPrevalence of HCV co-infection was low and there was no evidence of HIV-HCV co-transmission in this cohort of relatively young, predominantly minority, newly HIV-diagnosed MSM, most with early HIV infection, with high rates of high risk sexual behaviors, STI, and non-IDU. The low HCV prevalence in a group with high-risk behaviors for non-IDU HCV acquisition suggests an opportune time for targeted HCV prevention measures

    Public Health Ethics: Cases Spanning the Globe

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    Public health ethics can be seen both as the application of principles and norms to guide the practice of public health and as a process for identifying, analyzing, and resolving ethical issues inherent in the practice of public health. Public health ethics helps us decide what we should do and why. Although the practice of public health has always considered ethical issues, the emergence of public health ethics as a discipline is relatively new. Although rooted in bioethics and clinical and research ethics, public health ethics has many characteristics that set it apart. The defining characteristics are its focus on achieving social goods for populations while respecting individual rights and recognizing the interdependence of people. Currently there are few practical training resources for public health practitioners that consider ethical issues and dilemmas likely to arise in the practice of public health. In public health ethics training, we have found it advantageous to use cases to illustrate how ethical principles can be applied in practical ways to decision making. The use of cases encourages reflection and discussion of ethics, reinforces basic ethical concepts through application to concrete examples, highlights practical decision making, allows learners to consider different perspectives, and sensitizes learners to the complex, multidimensional context of issues in public health practice. The case-based approach (known as casuistry) contrasts with the theoretical approach to considering moral principles, rules, and theories. By describing scenarios, cases allow the learner to use ethical principles in the context of a realistic situation that sheds light on ethical challenges and illustrates how ethical principles can help in making practical decisions. This casebook comprises a broad range of cases from around the globe to highlight the ethical challenges of public health. For those new to public health ethics, Section I introduces public health ethics. Chapter 1, “Public Health Ethics: Global Cases, Practice, and Context” by Ortmann and colleagues, summarizes basic concepts and describes how public health ethics differ from bioethics, clinical ethics, and research ethics. The chapter also includes an approach for conducting an ethical analysis in public health. In Chap. 2, “Essential Cases in the Development of Public Health Ethics,” Lee, Spector-Bagdady, and Sakhuja highlight important events that shaped the practice of public health and explain how practitioners address and prevent ethical challenges. Section II is organized into chapters that discuss the following public health topics: • Resource allocation and priority setting • Disease prevention and control • Chronic disease prevention and health promotion • Environmental and occupational public health • Vulnerability and marginalized populations • International collaboration for global public health • Public health research We have invited some of the leading writers and thinkers in public health ethics to provide an overview of the major ethical considerations associated with each topic. The topic overviews offer the authors’ perspectives about applicable ethical theories, frameworks, and tools and draw attention to the cases that follow. The cases are meant to highlight the ethical issues in practice. Each represents the work of authors from around the globe who responded to a solicitation from the U.S. Centers for Disease Control and Prevention. We worked with the authors to ensure that each case included a concise articulation of a public health situation that raises ethical tensions, challenges, or concerns that require decisions or recommendations from public health officials or practitioners. The cases are presented in a standard format that includes a background, case description, discussion questions, and references. However, we also allowed for variation in the amount of detail provided in each section and the approach used to set up the case. Our goal was to include just enough contextual information to orient the reader who is not an expert in the case topic. We include the case setting, population, or intervention in question, legal or regulatory landscape, and questions to stimulate discussion on core ethical issues. Each case—although fictionalized—is as realistic as possible to reflect the ethical challenges that public health practitioners face daily. Sometimes the cases were based on actual or composite events. In these instances, the case details were modified to exclude identifying information that could be considered private, sensitive, or disputable by others involved in the case. We deliberately did not attempt to provide a resolution or solution for the cases. Often in public health practice, there is no single correct answer. Instead, ethical analysis in public health is a process to identify the ethical dimensions of the options available and to arrive at a decision that is ethically justifiable, through deliberation and consideration of relevant facts, values, and contexts. The cases and other writings in this book represent the opinions, findings, and conclusions of the authors and do not necessarily reflect the official position, views, or policies of the editors, the editors’ host institutions, or the authors’ host institutions. We decided which topic category to place the case in to best distribute the cases across chapters. However, you may note that some cases cross topic areas and could just as easily have been included in another chapter. This casebook is written for public health practitioners, including frontline workers, field epidemiology trainers and trainees, and managers, planners, and decision makers with an interest in learning about how to integrate ethical analysis in their day-to-day public health practice. However, the casebook will also be useful to instructors in schools of public health and public health students as well as to academic ethicists who can use the book to teach public health ethics and distinguish it from clinical and research ethics. Our hope is that the casebook will increase awareness and understanding of public health ethics and the value of ethical analysis in public health practice in all of its forms. This includes applied public health research; public health policy development, implementation, and evaluation; and public health decision making in national and international field settings and training programs. By emphasizing prospective practical decision making, rather than just presenting a theoretical academic discussion of ethical principles, we hope this casebook will serve as a useful tool to support instruction, debate, and dialogue about the nature of ethical challenges encountered in public health practice and how to resolve these challenges. We recommend discussing the cases in small groups and using the discussion questions, the ethical framework described in Chap. 1, and the information provided in the topic area overview sections as a starting place for exploring the ethical issues reflected in the cases. The ultimate goal of case-based learning is to develop skills in ethical analysis and decision making in daily public health practice. The ethical framework provides a convenient tool for putting our ideas into practice

    Simulating carbon capture by enhanced weathering with global croplands: an overview of key processes highlighting areas of future model development

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    Enhanced weathering (EW) aims to amplify a natural sink for CO2 by incorporating powdered silicate rock with high reactive surface area into agricultural soils. The goal is to achieve rapid dissolution of minerals and release of alkalinity with accompanying dissolution of CO2 into soils and drainage waters. EW could counteract phosphorus limitation and greenhouse gas (GHG) emissions in tropical soils, and soil acidification, a common agricultural problem studied with numerical process models over several decades. Here, we review the processes leading to soil acidification in croplands and how the soil weathering CO2 sink is represented in models. Mathematical models capturing the dominant processes and human interventions governing cropland soil chemistry and GHG emissions neglect weathering, while most weathering models neglect agricultural processes. We discuss current approaches to modelling EW and highlight several classes of model having the potential to simulate EW in croplands. Finally, we argue for further integration of process knowledge in mathematical models to capture feedbacks affecting both longer-term CO2 consumption and crop growth and yields

    Petroleum hydrocarbon rhizoremediation and soil microbial activity improvement via cluster root formation by wild proteaceae plant species

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    Rhizoremediation potential of different wild plant species for total (aliphatic) petroleum hydrocarbon (TPH)-contaminated soils was investigated. Three-week-old seedlings of Acacia inaequilatera, Acacia pyrifolia, Acacia stellaticeps, Banksia seminuda, Chloris truncata, Hakea prostrata, Hardenbergia violacea, and Triodia wiseana were transplanted in a soil contaminated with diesel and engine oil as TPH at pollution levels of 4,370 (TPH1) and 7,500 (TPH2) mg kg−1, and an uncontaminated control (TPH0). After 150 days, the presence of TPH negatively affected the plant growth, but the growth inhibition effect varied between the plant species. Plant growth and associated root biomass influenced the activity of rhizo-microbiome. The presence of B. seminuda, C. truncata, and H. prostrata significantly increased the TPH removal rate (up to 30% compared to the unplanted treatment) due to the stimulation of rhizosphere microorganisms. No significant difference was observed between TPH1 and TPH2 regarding the plant tolerance and rhizoremediation potentials of the three plant species. The presence of TPH stimulated cluster root formation in B. seminuda and H. prostrata which was associated with enhanced TPH remediation of these two members of Proteaceae family. These results indicated that B. seminuda, C. truncata, and H. prostrata wild plant species could be suitable candidates for the rhizoremediation of TPH-contaminated soil

    Tetraspanin (TSP-17) Protects Dopaminergic Neurons against 6-OHDA-Induced Neurodegeneration in <i>C. elegans</i>

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    Parkinson's disease (PD), the second most prevalent neurodegenerative disease after Alzheimer's disease, is linked to the gradual loss of dopaminergic neurons in the substantia nigra. Disease loci causing hereditary forms of PD are known, but most cases are attributable to a combination of genetic and environmental risk factors. Increased incidence of PD is associated with rural living and pesticide exposure, and dopaminergic neurodegeneration can be triggered by neurotoxins such as 6-hydroxydopamine (6-OHDA). In C. elegans, this drug is taken up by the presynaptic dopamine reuptake transporter (DAT-1) and causes selective death of the eight dopaminergic neurons of the adult hermaphrodite. Using a forward genetic approach to find genes that protect against 6-OHDA-mediated neurodegeneration, we identified tsp-17, which encodes a member of the tetraspanin family of membrane proteins. We show that TSP-17 is expressed in dopaminergic neurons and provide genetic, pharmacological and biochemical evidence that it inhibits DAT-1, thus leading to increased 6-OHDA uptake in tsp-17 loss-of-function mutants. TSP-17 also protects against toxicity conferred by excessive intracellular dopamine. We provide genetic and biochemical evidence that TSP-17 acts partly via the DOP-2 dopamine receptor to negatively regulate DAT-1. tsp-17 mutants also have subtle behavioral phenotypes, some of which are conferred by aberrant dopamine signaling. Incubating mutant worms in liquid medium leads to swimming-induced paralysis. In the L1 larval stage, this phenotype is linked to lethality and cannot be rescued by a dop-3 null mutant. In contrast, mild paralysis occurring in the L4 larval stage is suppressed by dop-3, suggesting defects in dopaminergic signaling. In summary, we show that TSP-17 protects against neurodegeneration and has a role in modulating behaviors linked to dopamine signaling

    Agronomic Management of Indigenous Mycorrhizas

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    Many of the advantages conferred to plants by arbuscular mycorrhiza (AM) are associated to the ability of AM plants to explore a greater volume of soil through the extraradical mycelium. Sieverding (1991) estimates that for each centimetre of colonized root there is an increase of 15 cm3 on the volume of soil explored, this value can increase to 200 cm3 depending on the circumstances. Due to the enhancement of the volume of soil explored and the ability of the extraradical mycelium to absorb and translocate nutrients to the plant, one of the most obvious and important advantages resulting from mycorrhization is the uptake of nutrients. Among of which the ones that have immobilized forms in soil, such as P, assume particular significance. Besides this, many other benefits are recognized for AM plants (Gupta et al, 2000): water stress alleviation (Augé, 2004; Cho et al, 2006), protection from root pathogens (Graham, 2001), tolerance to toxic heavy metals and phytoremediation (Audet and Charest, 2006; Göhre and Paszkowski, 2006), tolerance to adverse conditions such as very high or low temperature, high salinity (Sannazzaro et al, 2006), high or low pH (Yano and Takaki, 2005) or better performance during transplantation shock (Subhan et al, 1998). The extraradical hyphae also stabilize soil aggregates by both enmeshing soil particles (Miller e Jastrow, 1992) and producing a glycoprotein, golmalin, which may act as a glue-like substance to adhere soil particles together (Wright and Upadhyaya, 1998). Despite the ubiquous distribution of mycorrhizal fungi (Smith and Read, 2000) and only a relative specificity between host plants and fungal isolates (McGonigle and Fitter, 1990), the obligate nature of the symbiosis implies the establishment of a plant propagation system, either under greenhouse conditions or in vitro laboratory propagation. These techniques result in high inoculum production costs, which still remains a serious problem since they are not competitive with production costs of phosphorus fertilizer. Even if farmers understand the significance of sustainable agricultural systems, the reduction of phosphorus inputs by using AM fungal inocula alone cannot be justified except, perhaps, in the case of high value crops (Saioto and Marumoto, 2002). Nurseries, high income horticulture farmers and no-agricultural application such as rehabilitation of degraded or devegetated landscapes are examples of areas where the use of commercial inoculum is current. Another serious problem is quality of commercial available products concerning guarantee of phatogene free content, storage conditions, most effective application methods and what types to use. Besides the information provided by suppliers about its inoculum can be deceiving, as from the usually referred total counts, only a fraction may be effective for a particular plant or in specific soil conditions. Gianinazzi and Vosátka (2004) assume that progress should be made towards registration procedures that stimulate the development of the mycorrhizal industry. Some on-farm inoculum production and application methods have been studied, allowing farmers to produce locally adapted isolates and generate a taxonomically diverse inoculum (Mohandas et al, 2004; Douds et al, 2005). However the inocula produced this way are not readily processed for mechanical application to the fields, being an obstacle to the utilization in large scale agriculture, especially row crops, moreover it would represent an additional mechanical operation with the corresponding economic and soil compaction costs. It is well recognized that inoculation of AM fungi has a potential significance in not only sustainable crop production, but also environmental conservation. However, the status quo of inoculation is far from practical technology that can be widely used in the field. Together a further basic understanding of the biology and diversity of AM fungi is needed (Abbott at al, 1995; Saito and Marumoto, 2002). Advances in ecology during the past decade have led to a much more detailed understanding of the potential negative consequences of species introductions and the potential for negative ecological consequences of invasions by mycorrhizal fungi is poorly understood. Schwartz et al, (2006) recommend that a careful assessment documenting the need for inoculation, and the likelihood of success, should be conducted prior to inoculation because inoculations are not universally beneficial. Agricultural practices such as crop rotation, tillage, weed control and fertilizer apllication all produce changes in the chemical, physical and biological soil variables and affect the ecological niches available for occupancy by the soil biota, influencing in different ways the symbiosis performance and consequently the inoculum development, shaping changes and upset balance of native populations. The molecular biology tools developed in the latest years have been very important for our perception of these changes, ensuing awareness of management choice implications in AM development. In this context, for extensive farming systems and regarding environmental and economic costs, the identification of agronomic management practices that allow controlled manipulation of the fungal community and capitalization of AM mutualistic effect making use of local inoculum, seem to be a wise option for mycorrhiza promotion and development of sustainable crop production

    Lack of Antinociceptive Cross-Tolerance With Co-Administration of Morphine and Fentanyl Into the Periaqueductal Gray of Male Sprague-Dawley Rats

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    Tolerance to the antinociceptive effect of mu-opioid receptor (MOPr) agonists, such as morphine and fentanyl, greatly limits their effectiveness for long-term use to treat pain. Clinical studies have shown that combination therapy and opioid rotation can be used to enhance opioid-induced antinociception once tolerance has developed. The mechanism and brain regions involved in these processes are unknown. The purpose of this study was to evaluate the contribution of the ventrolateral periaqueductal gray (vlPAG) to antinociceptive tolerance and cross-tolerance between administration and co- administration of morphine and fentanyl. Tolerance was induced by pretreating rats with morphine or fentanyl or low-dose combination of morphine and fentanyl into the vlPAG followed by assessment of cross-tolerance to the other opioid. In addition, tolerance to the combined treatment was assessed. Cross-tolerance did not develop between repeated vlPAG microinjections of morphine and fentanyl. Likewise, there was no evidence of cross-tolerance from morphine or fentanyl to co-administration of morphine and fentanyl. Co-administration did not cause cross-tolerance to fentanyl. Cross- tolerance was only evident to morphine or morphine and fentanyl combined in rats pretreated with co-administration of low-doses of morphine and fentanyl. In conclusion, cross-tolerance does not develop between morphine and fentanyl within the vlPAG. This finding is consistent with the functionally selective signaling that has been reported for antinociception and tolerance following morphine and fentanyl binding to the MOPr. This research supports the notion that combination therapy and opioid rotation may be useful clinical practices to reduce opioid tolerance and other side effects. Perspective: This preclinical study shows that there is a reduction in cross tolerance between morphine and fentanyl within the periaqueductal gray which is key brain region in opioid antinociception and tolerance

    The added value of quantitative multi-voxel MR spectroscopy in breast magnetic resonance imaging

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    To determine whether quantitative multivoxel MRS improves the accuracy of MRI in the assessment of breast lesions. Twenty-five consecutive patients with 26 breast lesions a parts per thousand yen1 cm assessed as BI-RADS 3 or 4 with mammography underwent quantitative multivoxel MRS and contrast-enhanced MRI. The choline (Cho) concentration was calculated using the unsuppressed water signal as a concentration reference. ROC analysis established the diagnostic accuracy of MRI and MRS in the assessment of breast lesions. Respective Cho concentrations in 26 breast lesions re-classified by MRI as BI-RADS 2 (n = 5), 3 (n = 8), 4 (n = 5) and 5 (n = 8) were 1.16 +/- 0.43 (mean +/- SD), 1.43 +/- 0.47, 2.98 +/- 2.15 and 4.94 +/- 3.10 mM. Two BI-RADS 3 lesions and all BI-RADS 4 and 5 lesions were malignant on histopathology and had Cho concentrations between 1.7 and 11.8 mM (4.03 +/- 2.72 SD), which were significantly higher (P = 0.01) than that in the 11 benign lesions (0.4-1.5 mM; 1.19 +/- 0.33 SD). Furthermore, Cho concentrations in the benign and malignant breast lesions in BI-RADS 3 category differed (P = 0.01). The accuracy of combined multivoxel MRS/breast MRI BI-RADS re-classification (AUC = 1.00) exceeded that of MRI alone (AUC = 0.96 +/- 0.03). These preliminary data indicate that multivoxel MRS improves the accuracy of MRI when using a Cho concentration cut-off a parts per thousand currency sign1.5 mM for benign lesions. Key Points aEuro cent Quantitative multivoxel MR spectroscopy can improve the accuracy of contrast-enhanced breast MRI. aEuro cent Multivoxel-MRS can differentiate breast lesions by using the highest Cho-concentration. aEuro cent Multivoxel-MRS can exclude patients with benign breast lesions from further invasive diagnostic procedures

    Association of mixed hematopoietic chimerism with elevated circulating autoantibodies and chronic graft-versus-host disease occurrence.

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    International audienceBACKGROUND: Use of a reduced-intensity conditioning regimen before an allogeneic hematopoietic cell transplantation is frequently associated with an early state of mixed hematopoietic chimerism. Such a coexistence of both host and donor hematopoietic cells may influence posttransplant alloreactivity and may affect the occurrence and severity of acute and chronic graft-versus-host disease (GVHD) as well as the intensity of the graft-versus-leukemia effect. Here we evaluated the relation between chimerism state after reduced-intensity conditioning transplantation (RICT), autoantibody production, and chronic GVHD (cGVHD)-related pathology. METHODS: Chimerism state, circulating anticardiolipin, and antidouble stranded DNA autoantibody (Ab) titers as well as occurrence of cGVHD-like lesions were investigated in a murine RICT model. RESULTS: We observed a novel association between mixed chimerism state, high levels of pathogenic IgG autoantibodies, and subsequent development of cGVHD-like lesions. Furthermore, we found that the persistence of host B cells, but not dendritic cell origin or subset, was a factor associated with the appearance of cGVHD-like lesions. The implication of host B cells was confirmed by a host origin of autoantibodies. CONCLUSION: Recipient B cell persistence may contribute to the frequency and/or severity of cGVHD after RICT
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