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1.
Am J Physiol Endocrinol Metab ; 317(2): E200-E211, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31084499

RESUMO

Given the chemoattractant potential of complement factor 5 (C5) and its increased expression in adipose tissue (AT) of obese mice, we determined whether this protein of the innate immune system impacts insulin action. C5 control (C5cont) and spontaneously C5-deficient (C5def, B10.D2-Hc0 H2d H2-T18c/oSnJ) mice were placed on low- and high-fat diets to investigate their inflammatory and metabolic phenotypes. Adenoviral delivery was used to evaluate the effects of exogenous C5 on systemic metabolism. C5def mice gained less weight than controls while fed a high-fat diet, accompanied by reduced AT inflammation, liver mass, and liver triglyceride content. Despite these beneficial metabolic effects, C5def mice demonstrated severe glucose intolerance and systemic insulin resistance, as well as impaired insulin signaling in liver and AT. C5def mice also exhibited decreased expression of insulin receptor (INSR) gene and protein, as well as improper processing of pro-INSR. These changes were not due to the C5 deficiency alone as other C5-deficient models did not recapitulate the INSR processing defect; rather, in addition to the mutation in the C5 gene, whole genome sequencing revealed an intronic 31-bp deletion in the Insr gene in the B10.D2-Hc0 H2d H2-T18c/oSnJ model. Irrespective of the genetic defect, adenoviral delivery of C5 improved insulin sensitivity in both C5cont and C5def mice, indicating an insulin-sensitizing function of C5.


Assuntos
Complemento C5/deficiência , Complemento C5/genética , Intolerância à Glucose/genética , Doenças da Deficiência Hereditária de Complemento/patologia , Adenoviridae/genética , Animais , Complemento C5/fisiologia , Modelos Animais de Doenças , Metabolismo Energético/genética , Metabolismo Energético/imunologia , Intolerância à Glucose/metabolismo , Intolerância à Glucose/patologia , Doenças da Deficiência Hereditária de Complemento/genética , Resistência à Insulina/genética , Camundongos , Camundongos Endogâmicos AKR , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Endogâmicos DBA , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Transdução de Sinais/genética , Transdução Genética
2.
Bioethics ; 33(1): 35-42, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30198594

RESUMO

In 2004, the first ever multi-sited clinical trials studied the prospect of HIV biomedical prevention (referred to as pre-exposure prophylaxis-'PrEP'). The trials were implemented at several international sites, but many officially closed down before they completed. At most sites, both scientists and community AIDS advocates raised concerns over the ethics and scientific rationales of the trial. Focusing on the Nigerian trial site, we detail the controversy that emerged among mostly Nigerian research scientists who scrutinized the research design and protocol. While some of the disputes, especially those pertaining to community engagement mechanisms, were ultimately resolved in international fora and implemented in later PrEP trials, concerns over science rationales and assumptions were never addressed. We argue that scientific rationales should be treated as ethical concerns and suggest that such concerns should be deliberated at host sites before the trial protocol is finalized.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Pesquisa Biomédica/ética , Análise Ética , Infecções por HIV/prevenção & controle , Profilaxia Pré-Exposição , Pesquisadores/ética , Tenofovir/uso terapêutico , Síndrome da Imunodeficiência Adquirida/prevenção & controle , Participação da Comunidade , Dissidências e Disputas , Ética em Pesquisa , HIV , Humanos , Nigéria , Defesa do Paciente , Ensaios Clínicos Controlados Aleatórios como Assunto/ética , Projetos de Pesquisa , Pensamento/ética
5.
J Med Ethics ; 42(4): 209-10, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25205389

RESUMO

The recent wave of the Ebola Virus Disease (EVD) in Western Africa and efforts to control the disease where the health system requires strengthening raises a number of ethical challenges for healthcare workers practicing in these countries. We discuss the implications of weak health systems for controlling EVD and limitations of the ethical obligation to provide care for patients with EVD using Nigeria as a case study. We highlight the right of healthcare workers to protection that should be obligatorily provided by the government. Where the national government cannot meet this obligation, healthcare workers only have a moral and not a professional obligation to provide care to patients with EVD. The national government also has an obligation to adequately compensate healthcare workers that become infected in the course of duty. Institutionalisation of policies that protect healthcare workers are required for effective control of the spread of highly contagious diseases like EVD in a timely manner.


Assuntos
Planejamento em Saúde Comunitária/ética , Atenção à Saúde/ética , Surtos de Doenças , Pessoal de Saúde/ética , Doença pelo Vírus Ebola , Obrigações Morais , África Ocidental/epidemiologia , Códigos de Ética , Compensação e Reparação , Atenção à Saúde/economia , Ética Médica , Pessoal de Saúde/economia , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/terapia , Doença pelo Vírus Ebola/transmissão , Humanos , Nigéria/epidemiologia , Política Pública , Responsabilidade Social
6.
BMC Med Ethics ; 17: 10, 2016 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-26857351

RESUMO

BACKGROUND: The global interest in developing therapies for Ebola infection management and its prevention is laudable. However the plan to conduct an emergency immunization program specifically for healthcare workers using experimental vaccines raises some ethical concerns. This paper shares perspectives on these concerns and suggests how some of them may best be addressed. DISCUSSION: The recruitment of healthcare workers for Ebola vaccine research has challenges. It could result in coercion of initially dissenting healthcare workers to assist in the management of EVD infected persons due to mistaken beliefs that the vaccine offers protection. It could also affect equity and justice. For example, where people who are not skilled health care professionals but who provide care to patients infected with Ebola (such as in home care settings) are not prioritized for vaccination. The possibility of study participants contracting Ebola infection despite the use of experimental vaccine, and the standard of care they would receive, needs to be addressed clearly, transparently and formalized as part of the ethics review process. Future access to study products in view of current status of the TRIPS agreement needs to be addressed. Finally, broad stakeholder engagement at local, regional and international levels needs to be promoted using available communication channels to engage local, regional and international support. These same concerns are applicable for current and future epidemics. Successful Ebola vaccine development research requires concerted efforts at public dialogue to address misconceptions, equity and justice in participant selection, and honest discussions about risks, benefits and future access. Public dialogue about Ebola vaccine research plans is crucial and should be conducted by trusted locals and negotiated between communities, researchers and ethics committees in research study sites.


Assuntos
Pesquisa Biomédica/ética , Emergências , Doença pelo Vírus Ebola/prevenção & controle , Programas de Imunização/ética , Terapias em Estudo/ética , Vacinação , Vacinas Virais , Descoberta de Drogas , Ebolavirus , Epidemias , Ética em Pesquisa , Pessoal de Saúde , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/virologia , Humanos , Sujeitos da Pesquisa , Vacinas Virais/normas
7.
J Neuroinflammation ; 12: 171, 2015 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-26377670

RESUMO

BACKGROUND: HIV-associated neuroinflammation is believed to be a major contributing factor in the development of HIV-associated neurocognitive disorders (HAND). In this study, we used micropositron emission tomography (PET) imaging to quantify neuroinflammation in HIV-1 transgenic rat (Tg), a small animal model of HIV, known to develop neurological and behavioral problems. METHODS: Dynamic [(18)F]DPA-714 PET imaging was performed in Tg and age-matched wild-type (WT) rats in three age groups: 3-, 9-, and 16-month-old animals. As a positive control for neuroinflammation, we performed unilateral intrastriatal injection of quinolinic acid (QA) in a separate group of WT rats. To confirm our findings, we performed multiplex immunofluorescent staining for Iba1 and we measured cytokine/chemokine levels in brain lysates of Tg and WT rats at different ages. RESULTS: [(18)F]DPA-714 uptake in HIV-1 Tg rat brains was generally higher than in age-matched WT rats but this was not statistically significant in any age group. [(18)F]DPA-714 uptake in the QA-lesioned rats was significantly higher ipsilateral to the lesion compared to contralateral side indicating neuroinflammatory changes. Iba1 immunofluorescence showed no significant differences in microglial activation between the Tg and WT rats, while the QA-lesioned rats showed significant activation. Finally, cytokine/chemokine levels in brain lysates of the Tg rats and WT rats were not significantly different. CONCLUSION: Microglial activation might not be the primary mechanism for neuropathology in the HIV-1 Tg rats. Although [(18)F]DPA-714 is a good biomarker of neuroinflammation, it cannot be reliably used as an in vivo biomarker of neurodegeneration in the HIV-1 Tg rat.


Assuntos
Lesões Encefálicas/virologia , Encefalite/diagnóstico por imagem , Fluordesoxiglucose F18/farmacocinética , HIV-1/metabolismo , Tomografia por Emissão de Pósitrons , Pirazóis/farmacocinética , Pirimidinas/farmacocinética , Análise de Variância , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/genética , Lesões Encefálicas/induzido quimicamente , Lesões Encefálicas/complicações , Lesões Encefálicas/diagnóstico por imagem , Mapeamento Encefálico , Citocinas/metabolismo , Encefalite/etiologia , Fluordesoxiglucose F18/sangue , Lateralidade Funcional , HIV-1/genética , Masculino , Pirazóis/sangue , Pirimidinas/sangue , Ácido Quinolínico/toxicidade , Ratos , Ratos Endogâmicos F344 , Ratos Transgênicos , Fatores de Tempo
8.
BMC Infect Dis ; 15: 242, 2015 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-26113124

RESUMO

BACKGROUND: The current Ebola Virus Disease (EVD) outbreak in West Africa is the largest in history. As of February 18(th) 2015, 23,258 cases of EVD have been cumulatively reported from Nigeria, Senegal, Guinea, Liberia, Mali, Sierra Leone, Spain, the United Kingdom and the United States of America resulting in more than 9,000 deaths. It is therefore exigent to develop prevention and treatment therapies for EVD. DISCUSSION: Several new EVD treatments are in clinical development at this time. Based on lessons learned, four critical processes need to be implemented before clinical trials begin. First, all global EVD research need to be coordinated to promote data sharing and synergistic overlap, while reducing unnecessary duplication of efforts. The World Health Organization is well-placed to undertake such an endeavor. Second, governments of affected nations where trials are being proposed need to lead discussions regarding immediate access to any proven medications for epidemics. Also, governments need to leverage international resources to support and expand existing national expertise to jointly conduct high-caliber clinical research; and resources must be used to enhance local technical skills and expand existing personnel. Third, ethics committees must review protocols, monitor the research process, and work closely with research scientists to insure the ethical integrity of research throughout the trials. Fourth, community advisory boards (CAB) need to be formed, linked with existing community leadership structures and organized in conjunction with trial implementation. These community structures should work together with ethics committees to facilitate the study design, informed consent process, and study implementation. We must facilitate communication and mutual understanding between trial communities and research teams, and promote positive collaborations between all stakeholders engaged in EVD research. The community engagement process for EVD research is crucial to address myths and misconceptions, and to promote study volunteers' understanding of the research details. The collaboration between all stakeholders is crucial for continued long term partnership to address EVD outbreak and none of the stakeholders should be left behind in ongoing efforts to develop EVD therapies.


Assuntos
Pesquisa Biomédica/organização & administração , Doença pelo Vírus Ebola/epidemiologia , Área Carente de Assistência Médica , África Ocidental/epidemiologia , Antivirais/farmacologia , Antivirais/uso terapêutico , Surtos de Doenças/prevenção & controle , Ebolavirus/efeitos dos fármacos , Epidemias , Doença pelo Vírus Ebola/tratamento farmacológico , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Cooperação Internacional
9.
J Am Pharm Assoc (2003) ; 55(3): 313-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26003160

RESUMO

OBJECTIVE: To determine the incidence and cost of medications dispensed despite discontinuation (MDDD) of the medications in the electronic medical record within an integrated health care organization. SETTING: Dean Health System, with medical clinics and pharmacies linked by an electronic medical record, and a shared health plan and pharmacy benefits management company. PRACTICE DESCRIPTION: Pharmacist-led quality improvement project using retrospective chart review. PRACTICE INNOVATION: Electronic medical records, pharmacy records, and prescription claims data from patients 18 years of age or older who had a prescription filled for a chronic condition from June 2012 to August 2013 and submitted a claim through the Dean Health Plan were aggregated and cross-referenced to identify MDDD. MAIN OUTCOME MEASURES: Descriptive statistics were used to characterize demographics and MDDD incidence. Fisher's exact test and independent samples t tests were used to compare MDDD and non-MDDD groups. Wholesale acquisition cost was applied to each MDDD event. RESULTS: 7,406 patients met inclusion criteria. For 223 (3%) patients with MDDD, 253 independent events were identified. In terms of frequency per category, antihypertensive agents topped the list, followed, in descending order, by anticonvulsants, antilipemics, antidiabetics, and anticoagulants. Nine medications accounted for 59% (150 of 253) of all MDDD events; these included (again in descending order): gabapentin, atorvastatin, simvastatin, hydrochlorothiazide, lisinopril, warfarin, furosemide, metformin, and metoprolol. Mail-service pharmacies accounted for the highest incidence (5.3%) of MDDD, followed by mass merchandisers (4.6%) and small chains (3.9%). The total cost attributable to MDDD was $9,397.74. CONCLUSION: Development of a technology-based intervention to decrease the incidence of MDDD may be warranted to improve patient safety and decrease health care costs.


Assuntos
Custos de Medicamentos/estatística & dados numéricos , Registros Eletrônicos de Saúde , Planos de Sistemas de Saúde/economia , Prescrição Eletrônica/economia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Melhoria de Qualidade
10.
Dev World Bioeth ; 15(3): 214-25, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24975983

RESUMO

HIV prevention is a critical health issue in Nigeria; a country that has one of the worst HIV epidemic profiles in the world. With 270,000 new infections in 2012, Nigeria is a prime site for HIV prevention research. One effect of the HIV epidemic has been to revolutionalise ethical norms for the conduct of research: it is now considered unethical to design and implement HIV related studies without community engagement. Unfortunately, there is very little commensurate effort in building the capacity of local persons to engage actively with researchers, and there is no existing platform to facilitate dialogue between researchers and communities engaged in research in Nigeria. In an effort to address this gap, we undertook a series of three community dialogues (Phase One) and two community-researcher interface meetings (Phase Two) in Nigeria. This paper aims to give an empirical account of the dialogue from these community engagement processes and provide a resulting critique of the implementation of research ethics practices in Nigeria. It is anticipated that the outputs will: (i) support researchers in designing community-based research protocols; (ii) inform ethics committees of key considerations during research protocol reviews from a community perspective; and (iii) inform policy makers and research sponsors about issues of primary concern to communities with respect to HIV research.


Assuntos
Pesquisa Biomédica/ética , Infecções por HIV/prevenção & controle , Política de Saúde , Pesquisa Biomédica/organização & administração , Participação da Comunidade , Comunicação em Saúde , Humanos , Nigéria
11.
Anthropol Med ; 22(3): 278-94, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26422196

RESUMO

Between 2004 and 2005, the first multi-sited clinical trial tested whether an existing, marketed antiretroviral drug, Tenofovir (TDF), could prevent HIV transmission. Referred to as pre-exposure prophylaxis (PrEP), most of these trial sites prematurely closed down. Two sites located in Cambodia and Cameroon received international media attention. But little attention was drawn to sites in Malawi and Nigeria, where university ethicists and research scientists extensively debated PrEP. This article focuses on events that took place in Malawi where there was a prolonged dispute over the scientific rationales of PrEP and not trial specific ethics referred to as 'bioethics'. Specifically, the article discusses debates pertaining to three PrEP trial protocols that were refused ethics approval in Malawi between 2004 and 2009. It is argued that HIV science debates in Malawi are embedded in postcolonial politics--geopolitical histories and state and household economic dispossessions that have created the structural possibilities for Malawi to become an offshore destination for HIV clinical research. As such, ethics in this case does not pertain to trial or bioethical 'failures'. Rather, ethics is located at the scale of imperial relations that give rise to multiple, often invisible, research concerns and constraints.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Ensaios Clínicos como Assunto/ética , Infecções por HIV , Profilaxia Pré-Exposição , Falha de Tratamento , Antropologia Médica , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/etnologia , Infecções por HIV/prevenção & controle , Humanos , Malaui
12.
BMC Genomics ; 15: 376, 2014 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-24885832

RESUMO

BACKGROUND: We have a limited understanding of genomic interactions that occur among partners for many symbioses. One of the most important symbioses in tropical reef habitats involves Symbiodinium. Most work examining Symbiodinium-host interactions involves cnidarian partners. To fully and broadly understand the conditions that permit Symbiodinium to procure intracellular residency, we must explore hosts from different taxa to help uncover universal cellular and genetic strategies for invading and persisting in host cells. Here, we present data from gene expression analyses involving the bioeroding sponge Cliona varians that harbors Clade G Symbiodinium. RESULTS: Patterns of differential gene expression from distinct symbiont states ("normal", "reinfected", and "aposymbiotic") of the sponge host are presented based on two comparative approaches (transcriptome sequencing and suppressive subtractive hybridization (SSH)). Transcriptomic profiles were different when reinfected tissue was compared to normal and aposymbiotic tissue. We characterized a set of 40 genes drawn from a pool of differentially expressed genes in "reinfected" tissue compared to "aposymbiotic" tissue via SSH. As proof of concept, we determined whether some of the differentially expressed genes identified above could be monitored in sponges grown under ecologically realistic field conditions. We allowed aposymbiotic sponge tissue to become re-populated by natural pools of Symbiodinium in shallow water flats in the Florida Keys, and we analyzed gene expression profiles for two genes found to be increased in expression in "reinfected" tissue in both the transcriptome and via SSH. These experiments highlighted the experimental tractability of C. varians to explore with precision the genetic events that occur upon establishment of the symbiosis. We briefly discuss lab- and field-based experimental approaches that promise to offer insights into the co-opted genetic networks that may modulate uptake and regulation of Symbiondinium populations in hospite. CONCLUSIONS: This work provides a sponge transcriptome, and a database of putative genes and genetic pathways that may be involved in Symbiodinium interactions. The relative patterns of gene expression observed in these experiments will need to be evaluated on a gene-by-gene basis in controlled and natural re-infection experiments. We argue that sponges offer particularly useful characteristics for discerning essential dimensions of the Symbiodinium niche.


Assuntos
Dinoflagellida/genética , Perfilação da Expressão Gênica , Poríferos/genética , Simbiose/genética , Transcriptoma , Animais , Biologia Computacional , Regulação da Expressão Gênica , Anotação de Sequência Molecular , Reprodutibilidade dos Testes
13.
Mol Imaging ; 132014.
Artigo em Inglês | MEDLINE | ID: mdl-25248756

RESUMO

The dopaminergic system is especially vulnerable to the effects of human immunodeficiency virus (HIV) infection, rendering dopaminergic deficits early surrogate markers of HIV-associated neuropathology. We quantified dopamine D2/3 receptors in young HIV-1 transgenic (Tg) (n  =  6) and age-matched control rats (n  =  7) and adult Tg (n  =  5) and age-matched control rats (n  =  5) using [18F]fallypride positron emission tomography (PET). Regional uptake was quantified as binding potential (BPND) using the two-tissue reference model with the cerebellum as the reference. Time-activity curves were generated for the ventral striatum, dorsal striatum, thalamus, and cerebellum. Whereas BPND values were significantly lower in the ventral striatum (p < .001) and dorsal striatum (p  =  .001) in the adult Tg rats compared to controls rats, they were significantly lower only in the dorsal striatum (p < .05) in the young rats. Tg rats had smaller striatal volumes on magnetic resonance imaging. We also found lower expression levels of tyrosine hydroxylase on immunohistochemistry in the Tg animals. Our findings suggest that progressive striatal D2/3 receptor deficits occur in Tg rats as they age and can be detected using small-animal PET imaging. The effectiveness of various approaches in preventing or halting this dopaminergic loss in the Tg rat can thus be measured preclinically using [18F]fallypride PET as a molecular imaging biomarker of HIV-associated neuropathology.


Assuntos
Benzamidas/farmacocinética , Encéfalo/diagnóstico por imagem , Infecções por HIV/diagnóstico por imagem , Pirrolidinas/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Animais , Biomarcadores/análise , Encéfalo/metabolismo , Modelos Animais de Doenças , Infecções por HIV/metabolismo , Infecções por HIV/patologia , HIV-1/fisiologia , Humanos , Tomografia por Emissão de Pósitrons/métodos , Ratos , Ratos Transgênicos , Receptores de Dopamina D2/análise , Receptores de Dopamina D3/análise
14.
J Law Med Ethics ; 52(S1): 31-34, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38995249

RESUMO

Cross jurisdictional collaboration efforts and emergency vaccine plans that are consistent with Tribal sovereignty are essential to public health emergency preparedness. The widespread adoption of clearly written federal, state, and local vaccine plans that address fundamental assumptions in vaccine distribution to Tribal nations is imperative for future pandemic response.


Assuntos
Vacinas , Humanos , Planejamento em Desastres , Governo Federal , Indígenas Norte-Americanos , Governo Estadual , Estados Unidos , Vacinas/provisão & distribuição
16.
Syst Biol ; 58(2): 224-39, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20525580

RESUMO

We present a 6-gene, 420-species maximum-likelihood phylogeny of Ascomycota, the largest phylum of Fungi. This analysis is the most taxonomically complete to date with species sampled from all 15 currently circumscribed classes. A number of superclass-level nodes that have previously evaded resolution and were unnamed in classifications of the Fungi are resolved for the first time. Based on the 6-gene phylogeny we conducted a phylogenetic informativeness analysis of all 6 genes and a series of ancestral character state reconstructions that focused on morphology of sporocarps, ascus dehiscence, and evolution of nutritional modes and ecologies. A gene-by-gene assessment of phylogenetic informativeness yielded higher levels of informativeness for protein genes (RPB1, RPB2, and TEF1) as compared with the ribosomal genes, which have been the standard bearer in fungal systematics. Our reconstruction of sporocarp characters is consistent with 2 origins for multicellular sexual reproductive structures in Ascomycota, once in the common ancestor of Pezizomycotina and once in the common ancestor of Neolectomycetes. This first report of dual origins of ascomycete sporocarps highlights the complicated nature of assessing homology of morphological traits across Fungi. Furthermore, ancestral reconstruction supports an open sporocarp with an exposed hymenium (apothecium) as the primitive morphology for Pezizomycotina with multiple derivations of the partially (perithecia) or completely enclosed (cleistothecia) sporocarps. Ascus dehiscence is most informative at the class level within Pezizomycotina with most superclass nodes reconstructed equivocally. Character-state reconstructions support a terrestrial, saprobic ecology as ancestral. In contrast to previous studies, these analyses support multiple origins of lichenization events with the loss of lichenization as less frequent and limited to terminal, closely related species.


Assuntos
Ascomicetos/genética , Filogenia , Ascomicetos/classificação , Ascomicetos/citologia , Ecossistema , Genes Fúngicos , Reprodução
17.
Mycologia ; 102(6): 1398-416, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20943539

RESUMO

Cyttaria species (Leotiomycetes, Cyttariales) are obligate, biotrophic associates of Nothofagus (Hamamelididae, Nothofagaceae), the southern beech. As such Cyttaria species are restricted to the southern hemisphere, inhabiting southern South America (Argentina and Chile) and southeastern Australasia (southeastern Australia including Tasmania, and New Zealand). The relationship of Cyttaria to other Leotiomycetes and the relationships among species of Cyttaria were investigated with newly generated sequences of partial nucSSU, nucLSU and mitSSU rRNA, as well as TEF1 sequence data and morphological data. Results found Cyttaria to be defined as a strongly supported clade. There is evidence for a close relationship between Cyttaria and these members of the Helotiales: Cordierites, certain Encoelia spp., Ionomidotis and to a lesser extent Chlorociboria. Order Cyttariales is supported by molecular data, as well as by the unique endostromatic apothecia, lack of chitin and highly specific habit of Cyttaria species. Twelve Cyttaria species are hypothesized, including all 11 currently accepted species plus an undescribed species that accommodates specimens known in New Zealand by the misapplied name C. gunnii, as revealed by molecular data. Thus the name C. gunnii sensu stricto is reserved for specimens occurring on N. cunninghamii in Australia, including Tasmania. Morphological data now support the continued recognition of C. septentrionalis as a species separate from C. gunnii. Three major clades are identified within Cyttaria: one in South America hosted by subgenus Nothofagus, another in South America hosted by subgenera Nothofagus and Lophozonia, and a third in South America and Australasia hosted by subgenus Lophozonia, thus producing a non-monophyletic grade of South American species and a monophyletic clade of Australasian species, including monophyletic Australian and New Zealand clades. Cyttaria species do not sort into clades according to their associations with subgenera Lophozonia and Nothofagus.


Assuntos
Ascomicetos/classificação , Ascomicetos/citologia , Núcleo Celular/genética , DNA Fúngico/genética , DNA Mitocondrial/genética , Filogenia , Ascomicetos/genética , Dados de Sequência Molecular
18.
Mycologia ; 102(6): 1417-25, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20943538

RESUMO

The obligate, biotrophic association among species of the fungal genus Cyttaria and their hosts in the plant genus Nothofagus often is cited as a classic example of cophylogeny and is one of the few cases in which the biogeography of a fungus is commonly mentioned or included in biogeographic analyses. In this study molecular and morphological data are used to examine hypotheses regarding the cophylogeny and biogeography of the 12 species of Cyttaria and their hosts, the 11 species of Nothofagus subgenera Lophozonia and Nothofagus. Our results indicate highly significant overall cophylogenetic structure, despite the fact that the associations between species of Cyttaria and Nothofagus usually do not correspond in a simple one to one relationship. Two major lineages of Cyttaria are confined to a single Nothofagus subgenus, a specificity that might account for a minimum of two codivergences. We hypothesize other major codivergences. Numerous extinction also are assumed, as are an independent parasite divergence followed by host switching to account for C. berteroi. Considering the historical association of Cyttaria and Nothofagus, our hypothesis may support the vicariance hypothesis for the trans-Antarctic distribution between Australasian and South American species of Cyttaria species hosted by subgenus Lophozonia. It also supports the hypothesis of transoceanic long distance dispersal to account for the relatively recent relationship between Australian and New Zealand Cyttaria species, which we estimate to have occurred 44.6-28.5 mya. Thus the history of these organisms is not only a reflection of the breakup of Gondwana but also of other events that have contributed to the distributions of many other southern hemisphere plants and fungi.


Assuntos
Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Fagus/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Ascomicetos/genética , Evolução Molecular , Geografia , Especificidade da Espécie
20.
Glob Bioeth ; 31(1): 47-66, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32921972

RESUMO

In 2004 and 2005, the first clinical trials were launched to investigate the use of tenofovir for HIV prevention in Cambodia,Cameroon, Nigeria and Thailand. Controversies erupted over the ethical integrity of the research protocol. We reflect on the events that ledto the controversies and identified that scientific and ethical concerns raised by members of local communities at each of these sites wereerased by trialists, causing crisis that led to premature shut down the early PrEP trials. In the aftermath of these trials, the World HealthOrganisation, UNAIDS, and AVAC developed ethics guidelines intended to recognize the concerns as authentic, and developed guidelines toimprove researchers' engagement of communities in biomedical HIV prevention trial design and implementation. Our findings suggest thatthe ethics guidelines are limited in its ability to address power inequalities that leads to voice erasures and non-recognition of localcompetencies. Rather the ethical documents enabled trialists to gain a new sense of authority through the interpretations of ethical researchconduct enabling trialists regain power that can further entrench inequality and voice erasures. To address concerns with what seems anintractable problem, we suggested models of engagement for off-shored research may be the option.

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