RESUMEN
HIV Nef counteracts cellular host restriction factors SERINC3 and SERINC5, but our understanding of how naturally occurring global Nef sequence diversity impacts these activities is limited. Here, we quantify SERINC3 and SERINC5 internalization function for 339 Nef clones, representing the major pandemic HIV-1 group M subtypes A, B, C and D. We describe distinct subtype-associated hierarchies for Nef-mediated internalization of SERINC5, for which subtype B clones display the highest activities on average, and of SERINC3, for which subtype B clones display the lowest activities on average. We further identify Nef polymorphisms that modulate its ability to counteract SERINC proteins, including substitutions in the N-terminal domain that selectively impair SERINC3 internalization. Our findings demonstrate that the SERINC antagonism activities of HIV Nef differ markedly among major viral subtypes and between individual isolates within a subtype, suggesting that variation in these functions may contribute to global differences in viral pathogenesis.
Asunto(s)
Infecciones por VIH/virología , VIH-1/fisiología , Glicoproteínas de Membrana/antagonistas & inhibidores , Proteínas de la Membrana/antagonistas & inhibidores , Polimorfismo Genético , Replicación Viral , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/metabolismo , Infecciones por VIH/genética , Infecciones por VIH/metabolismo , Seropositividad para VIH , Interacciones Huésped-Patógeno , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/virología , Células Tumorales Cultivadas , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/genéticaRESUMEN
Downregulation of BST-2/tetherin and CD4 by HIV-1 viral protein U (Vpu) promotes viral egress and allows infected cells to evade host immunity. Little is known however about the natural variability in these Vpu functions among the genetically diverse viral subtypes that contribute to the HIV-1 pandemic. We collected Vpu isolates from 332 treatment-naive individuals living with chronic HIV-1 infection in Uganda, Rwanda, South Africa, and Canada. Together, these Vpu isolates represent four major HIV-1 group M subtypes (A [n = 63], B [n = 84], C [n = 94], and D [n = 59]) plus intersubtype recombinants and uncommon strains (n = 32). The ability of each Vpu clone to downregulate endogenous CD4 and tetherin was quantified using flow cytometry following transfection into an immortalized T-cell line and compared to that of a reference Vpu clone derived from HIV-1 subtype B NL4.3. Overall, the median CD4 downregulation function of natural Vpu isolates was similar to that of NL4.3 (1.01 [interquartile range {IQR}, 0.86 to 1.18]), while the median tetherin downregulation function was moderately lower than that of NL4.3 (0.90 [0.79 to 0.97]). Both Vpu functions varied significantly among HIV-1 subtypes (Kruskal-Wallis P < 0.0001). Specifically, subtype C clones exhibited the lowest CD4 and tetherin downregulation activities, while subtype D and B clones were most functional for both activities. We also identified Vpu polymorphisms associated with CD4 or tetherin downregulation function and validated six of these using site-directed mutagenesis. Our results highlight the marked extent to which Vpu function varies among global HIV-1 strains, raising the possibility that natural variation in this accessory protein may contribute to viral pathogenesis and/or spread.IMPORTANCE The HIV-1 accessory protein Vpu enhances viral spread by downregulating CD4 and BST-2/tetherin on the surface of infected cells. Natural variability in these Vpu functions may contribute to HIV-1 pathogenesis, but this has not been investigated among the diverse viral subtypes that contribute to the HIV-1 pandemic. In this study, we found that Vpu function differs significantly among HIV-1 subtypes A, B, C, and D. On average, subtype C clones displayed the lowest ability to downregulate both CD4 and tetherin, while subtype B and D clones were more functional. We also identified Vpu polymorphisms that associate with functional differences among HIV-1 isolates and subtypes. Our study suggests that genetic diversity in Vpu may play an important role in the differential pathogenesis and/or spread of HIV-1.
Asunto(s)
Antígenos CD/biosíntesis , Antígenos CD4/biosíntesis , Regulación hacia Abajo , Infecciones por VIH , VIH-1/metabolismo , Proteínas del Virus de la Inmunodeficiencia Humana/metabolismo , Proteínas Reguladoras y Accesorias Virales/metabolismo , Antígenos CD/genética , Antígenos CD4/genética , Línea Celular Transformada , Enfermedad Crónica , Proteínas Ligadas a GPI/biosíntesis , Proteínas Ligadas a GPI/genética , VIH-1/genética , Proteínas del Virus de la Inmunodeficiencia Humana/genética , Humanos , Proteínas Reguladoras y Accesorias Virales/genéticaRESUMEN
The extent to which viral genetic context influences HIV adaptation to human leukocyte antigen (HLA) class I-restricted immune pressures remains incompletely understood. The Ugandan HIV epidemic, where major pandemic group M subtypes A1 and D cocirculate in a single host population, provides an opportunity to investigate this question. We characterized plasma HIV RNA gag, pol, and nef sequences, along with host HLA genotypes, in 464 antiretroviral-naive individuals chronically infected with HIV subtype A1 or D. Using phylogenetically informed statistical approaches, we identified HLA-associated polymorphisms and formally compared their strengths of selection between viral subtypes. A substantial number (32%) of HLA-associated polymorphisms identified in subtype A1 and/or D had previously been reported in subtype B, C, and/or circulating recombinant form 01_AE (CRF01_AE), confirming the shared nature of many HLA-driven escape pathways regardless of viral genetic context. Nevertheless, 34% of the identified HLA-associated polymorphisms were significantly differentially selected between subtypes A1 and D. Experimental investigation of select examples of subtype-specific escape revealed distinct underlying mechanisms with important implications for vaccine design: whereas some were attributable to subtype-specific sequence variation that influenced epitope-HLA binding, others were attributable to differential mutational barriers to immune escape. Overall, our results confirm that HIV genetic context is a key modulator of viral adaptation to host cellular immunity and highlight the power of combined bioinformatic and mechanistic studies, paired with knowledge of epitope immunogenicity, to identify appropriate viral regions for inclusion in subtype-specific and universal HIV vaccine strategies.IMPORTANCE The identification of HIV polymorphisms reproducibly selected under pressure by specific HLA alleles and the elucidation of their impact on viral function can help identify immunogenic viral regions where immune escape incurs a fitness cost. However, our knowledge of HLA-driven escape pathways and their functional costs is largely limited to HIV subtype B and, to a lesser extent, subtype C. Our study represents the first characterization of HLA-driven adaptation pathways in HIV subtypes A1 and D, which dominate in East Africa, and the first statistically rigorous characterization of differential HLA-driven escape across viral subtypes. The results support a considerable impact of viral genetic context on HIV adaptation to host HLA, where HIV subtype-specific sequence variation influences both epitope-HLA binding and the fitness costs of escape. Integrated bioinformatic and mechanistic characterization of these and other instances of differential escape could aid rational cytotoxic T-lymphocyte-based vaccine immunogen selection for both subtype-specific and universal HIV vaccines.
Asunto(s)
Técnicas de Genotipaje/métodos , Infecciones por VIH/sangre , VIH-1/patogenicidad , Antígenos HLA/genética , Proteínas del Virus de la Inmunodeficiencia Humana/genética , Vacunas contra el SIDA , Genotipo , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-1/clasificación , VIH-1/genética , VIH-1/inmunología , Antígenos HLA/sangre , Proteínas del Virus de la Inmunodeficiencia Humana/sangre , Humanos , Evasión Inmune , Inmunidad Celular , Filogenia , Polimorfismo Genético , Uganda , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/sangre , Productos del Gen gag del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/sangre , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen pol del Virus de la Inmunodeficiencia Humana/sangre , Productos del Gen pol del Virus de la Inmunodeficiencia Humana/genéticaRESUMEN
Carnivore predation on livestock is a complex management and policy challenge, yet it is also intrinsically an ecological interaction between predators and prey. Human-wildlife interactions occur in socioecological systems in which human and environmental processes are closely linked. However, underlying human-wildlife conflict and key to unpacking its complexity are concrete and identifiable ecological mechanisms that lead to predation events. To better understand how ecological theory accords with interactions between wild predators and domestic prey, we developed a framework to describe ecological drivers of predation on livestock. We based this framework on foundational ecological theory and current research on interactions between predators and domestic prey. We used this framework to examine ecological mechanisms (e.g., density-mediated effects, behaviorally mediated effects, and optimal foraging theory) through which specific management interventions operate, and we analyzed the ecological determinants of failure and success of management interventions in 3 case studies: snow leopards (Panthera uncia), wolves (Canis lupus), and cougars (Puma concolor). The varied, context-dependent successes and failures of the management interventions in these case studies demonstrated the utility of using an ecological framework to ground research and management of carnivore-livestock conflict. Mitigation of human-wildlife conflict appears to require an understanding of how fundamental ecological theories work within domestic predator-prey systems.
Un Marco de Trabajo Ecológico para Contextualizar el Conflicto Carnívoro - Ganado Resumen La depredación del ganado por carnívoros es un reto complejo para el manejo y las políticas, a pesar de que es intrínsecamente una interacción ecológica entre depredadores y presas. Las interacciones entre humanos y la fauna ocurren en sistemas socio-ecológicos en los que los humanos y los procesos ambientales están conectados estrechamente. Sin embargo, el conflicto humano - fauna subyacente y la clave para desenredar su complejidad son mecanismos ecológicos complejos e identificables que resultan en eventos de depredación. Para tener un mejor entendimiento sobre cómo la teoría ecológica armoniza con las interacciones entre los depredadores silvestres y la presa doméstica, desarrollamos un marco de trabajo para describir las causantes ecológicas de la depredación del ganado. Basamos este marco de trabajo en las principales teorías ecológicas y las investigaciones actuales sobre las interacciones entre los depredadores y las presas domésticas. Usamos este marco de trabajo para examinar los mecanismos ecológicos (es decir, los efectos mediados por la densidad, los efectos mediados por el comportamiento, y la teoría del forrajeo óptimo) mediante los cuales operan ciertas intervenciones específicas de manejo y analizamos las determinantes ecológicas del fracaso y el éxito de las intervenciones de manejo en tres estudios de caso: el leopardo de las nieves (Panthera uncia), el lobo (Canis lupus), y el puma (Puma concolor). Los éxitos y fracasos variados y dependientes del contexto que sufrieron las intervenciones de manejo en estos estudios de caso demostraron la utilidad del uso de un marco de trabajo ecológico para aterrizar la investigación y el manejo del conflicto carnívoro - ganado. La mitigación del conflicto humano - fauna parece requerir de un entendimiento sobre cómo funcionan las teorías ecológicas fundamentales dentro del sistema doméstico depredador - presa.
Asunto(s)
Carnívoros , Lobos , Animales , Animales Salvajes , Conservación de los Recursos Naturales , Humanos , Ganado , Conducta PredatoriaRESUMEN
The maturation process of high-affinity antibodies is a result of intricate interactions between B cells and follicular helper T (Tfh) cells occurring in lymphoid germinal centers. HIV infection induces significant chronic immune activation, phenotypic skewing, and inflammation driven by years of continuous viral replication. High levels of viremia as well as immune activation and dysfunction have been demonstrated to have a perturbing impact on the B cell memory compartment and contribute to B cell exhaustion. Counterintuitively, the factors associated with perturbation of the B cell compartment seem to be favorable for the generation of highly affinity-matured Env-specific antibodies in a minority of HIV-infected individuals. Thus, the impact of HIV antigenemia on B cells and Tfh cell interactions warrants further exploration. We therefore studied immunophenotypes of HIV-specific B cells in individuals with differing levels of viral control using HIV Env gp120 probes and characterized the functionality of matched T cells in peripheral blood. While CXCR5+ CD4+ T cells were significantly diminished in HIV progressors, we found that a small subset of gp120-specific interleukin-21 (IL-21)-secreting CXCR5+ CD4+ T cells were significantly associated with gp120-specific B cell frequencies. In contrast, neither bulk CXCR5+ CD4+ T cells nor other HIV antigen specificities were associated with gp120-specific B cell levels. HIV-specific B cells derived from elite controllers displayed greater amounts of gp120-specific B cells in the resting memory subset, whereas HIV-specific B cells in progressors accumulated in tissue-like and activated memory subsets. Furthermore, CXCR5+ CD4+ T cells from elite controllers showed a stronger ex vivo capacity to induce B cell maturation and immunoglobulin class switching than cells from HIV progressors.IMPORTANCE Dissecting the factors that are involved in B cell maturation and antibody development is important for HIV vaccine design. In this study, we found that HIV Env-specific CXCR5+ CD4+ T cells that secrete interleukin-21 are strongly associated with B cell memory phenotypes and function. Moreover, we found that the immune responses of HIV controllers showed intrinsically better helper activity than those of HIV progressors.
Asunto(s)
Linfocitos B/inmunología , Centro Germinal/inmunología , Proteína gp120 de Envoltorio del VIH/inmunología , Infecciones por VIH/inmunología , Sobrevivientes de VIH a Largo Plazo , Linfocitos T Colaboradores-Inductores/inmunología , Adulto , Linfocitos T CD4-Positivos/química , Linfocitos T CD4-Positivos/inmunología , Femenino , Humanos , Inmunofenotipificación , Interleucinas/metabolismo , Masculino , Persona de Mediana Edad , Receptores CXCR5/análisisRESUMEN
BACKGROUND: A 17-year-old boy on long-term immunosuppression following renal transplantation for chronic kidney disease (CKD), the result of dysplastic kidneys, initially presented with a swelling in his neck while attending hospital for an unrelated problem. A clinical diagnosis of tonsillitis was made, and he was treated with broad-spectrum antibiotics. Over a few days, his condition deteriorated, and he developed multiple vesicopustular skin lesions and required an emergency tonsillectomy due to respiratory distress. CASE DIAGNOSIS/TREATMENT: Histological investigation of the skin and tonsillar tissue suggested a viral aetiology, and subsequent electron microscopy and polymerase chain reaction (PCR) tissue examination proved disseminated cowpox infection. The family cat, which was reported as having self-resolving sores on its skin, was likely the source of the infection. The child failed to respond to antiviral treatment and succumbed to multiorgan failure within a month of admission. CONCLUSIONS: We report this case of fatal disseminated cowpox infection to highlight an increasing risk of this illness in the post-transplant population and to detail some unusual features not previously described, such as tonsillar involvement, disseminated skin lesions and multiorgan failure.
Asunto(s)
Viruela Vacuna/virología , Trasplante de Riñón/efectos adversos , Adolescente , Antibacterianos/uso terapéutico , Viruela Vacuna/patología , Virus de la Viruela Vacuna/genética , Resultado Fatal , Humanos , Masculino , Insuficiencia Multiorgánica/etiología , Reacción en Cadena de la Polimerasa , Insuficiencia Renal Crónica/cirugía , Enfermedades de la Piel/etiología , Enfermedades de la Piel/virología , Tonsilitis/tratamiento farmacológico , Receptores de TrasplantesAsunto(s)
Infecciones Oportunistas Relacionadas con el SIDA , Prestación Integrada de Atención de Salud , Infecciones por VIH/complicaciones , Sarcoma de Kaposi/patología , Neoplasias Cutáneas/patología , África del Sur del Sahara , Biopsia , Botswana , Dermatología , Salud Global , Humanos , Kenia , Nigeria , Derivación y Consulta , Sarcoma de Kaposi/diagnóstico , Neoplasias Cutáneas/diagnósticoRESUMEN
Effective implementation of the Environmental Impact Assessment (EIA) is recognised as a global issue, in particular the impact prediction stage, which is the 'core' of EIA. Consisting of four stages: impact identification, impact assessment, significance evaluation, and mitigation measures on the possible environmental repercussions of project developmental activities, the efficacy of impact prediction can define the quality of the EIA process, which will better align environmental decision-making to sustainable development. The weakness of impact prediction in EIA demands more study to enhance practice. Although this is widely explored in the context of developed countries such as the UK, it is particularly concerning in India. A specialised review package built from several sources is utilised to assess the efficacy of air quality impact prediction, based on Lee & Colley (1991). 20 EIA reports of Category A (mega-scale projects causing significant environmental impacts) are reviewed. This study's evaluation indicates that significance evaluation and mitigation actions are the weakest phases and a major concern while assessing air quality studies conducted as a part of EIA. Recommendations to improve the process include prioritising the cumulative impact assessment within the regulatory framework, enhancing capacity building, embedding public participation and instilling accountability among stakeholders, which can be adopted globally. Additional recommendations specifically for India are revising the National Ambient Air Quality Standards (NAAQS), restructuring the EIA review mechanism by EAC and improving mitigation measures by adopting GIS and remote sensing technologies.
RESUMEN
BACKGROUND: The highly genetically diverse HIV-1 group M subtypes may differ in their biological properties. Nef is an important mediator of viral pathogenicity; however, to date, a comprehensive inter-subtype comparison of Nef in vitro function has not been undertaken. Here, we investigate two of Nef's most well-characterized activities, CD4 and HLA class I downregulation, for clones obtained from 360 chronic patients infected with HIV-1 subtypes A, B, C or D. RESULTS: Single HIV-1 plasma RNA Nef clones were obtained from N=360 antiretroviral-naïve, chronically infected patients from Africa and North America: 96 (subtype A), 93 (B), 85 (C), and 86 (D). Nef clones were expressed by transfection in an immortalized CD4+ T-cell line. CD4 and HLA class I surface levels were assessed by flow cytometry. Nef expression was verified by Western blot. Subset analyses and multivariable linear regression were used to adjust for differences in age, sex and clinical parameters between cohorts. Consensus HIV-1 subtype B and C Nef sequences were synthesized and functionally assessed. Exploratory sequence analyses were performed to identify potential genotypic correlates of Nef function. Subtype B Nef clones displayed marginally greater CD4 downregulation activity (p = 0.03) and markedly greater HLA class I downregulation activity (p < 0.0001) than clones from other subtypes. Subtype C Nefs displayed the lowest in vitro functionality. Inter-subtype differences in HLA class I downregulation remained statistically significant after controlling for differences in age, sex, and clinical parameters (p < 0.0001). The synthesized consensus subtype B Nef showed higher activities compared to consensus C Nef, which was most pronounced in cells expressing lower protein levels. Nef clones exhibited substantial inter-subtype diversity: cohort consensus residues differed at 25% of codons, while a similar proportion of codons exhibited substantial inter-subtype differences in major variant frequency. These amino acids, along with others identified in intra-subtype analyses, represent candidates for mediating inter-subtype differences in Nef function. CONCLUSIONS: Results support a functional hierarchy of subtype B > A/D > C for Nef-mediated CD4 and HLA class I downregulation. The mechanisms underlying these differences and their relevance to HIV-1 pathogenicity merit further investigation.
Asunto(s)
Antígenos CD4/biosíntesis , VIH-1/fisiología , Antígenos de Histocompatibilidad Clase I/biosíntesis , Interacciones Huésped-Patógeno , Productos del Gen nef del Virus de la Inmunodeficiencia Humana/metabolismo , Adulto , África , Linfocitos T CD4-Positivos/virología , Línea Celular , Regulación hacia Abajo , Femenino , Genotipo , Infecciones por VIH/virología , VIH-1/clasificación , VIH-1/genética , VIH-1/aislamiento & purificación , Humanos , Masculino , América del NorteRESUMEN
Papillon-Lefèvre syndrome is characterised by palmoplantar keratoderma, periodontitis and pyogenic infections. We describe the first case of brain abscess in a child with this syndrome. We highlight the importance of recognising any associated diagnosis, however rare or apparently irrelevant, in an acutely and critically ill child.
Asunto(s)
Absceso Encefálico/complicaciones , Enfermedad de Papillon-Lefevre/complicaciones , Antibacterianos/uso terapéutico , Encéfalo/diagnóstico por imagen , Absceso Encefálico/patología , Absceso Encefálico/terapia , Preescolar , Medios de Contraste , Descompresión Quirúrgica , Humanos , Masculino , Enfermedad de Papillon-Lefevre/patología , Enfermedad de Papillon-Lefevre/terapia , Tomografía Computarizada por Rayos XRESUMEN
Following the near extinction of bison (Bison bison) from its historic range across North America in the late 19th century, novel bison conservation efforts in the early 20th century catalyzed a popular widespread conservation movement to protect and restore bison among other species and places. Since Allen's initial delineation (1876) of the historic distribution of North American bison, subsequent attempts have been hampered by knowledge gaps about bison distribution and abundance prior to and following colonial arrival and settlement. For the first time, we applied a multidisciplinary approach to assemble a comprehensive, integrated geographic database and meta-analysis of bison occurrence over the last 200,000 years, with particular emphasis on the 450 years before present. We combined paleontology, archaeology, and historical ecology data for our database, which totaled 6438 observations. We derived the observations from existing online databases, published literature, and first-hand exploration journal entries. To illustrate the conservative maximum historical extent of occurrence of bison, we created a concave hull using observations occurring over the last 450 years (n = 3379 observations), which is the broadly accepted historical benchmark at 1500 CE covering 59% of the North American continent. Although this distribution represents a historic extent of occurrence-merely delineating the maximum margins of the near-continental distribution-it does not replace a density-based approach reconstructing potential historical range distributions, which identifies core and marginal ranges. However, we envision the observations contained in this database will contribute to further research in the increasingly evidence-based disciplines of bison ecology, evolution, rewilding, management, and conservation. There are no copyright or proprietary restrictions on these data, and this data paper should be cited when the data are reused.
Asunto(s)
Bison , Animales , América del Norte , EcologíaRESUMEN
Osteosarcoma is a primary bone malignancy with a particularly high incidence rate in children and adolescents relative to other age groups. The etiology of this often aggressive cancer is currently unknown, because complicated structural and numeric genomic rearrangements in cancer cells preclude understanding of tumour development. In addition, few consistent genetic changes that may indicate effective molecular therapeutic targets have been reported. However, high-resolution techniques continue to improve knowledge of distinct areas of the genome that are more commonly associated with osteosarcomas. Copy number gains at chromosomes 1p, 1q, 6p, 8q, and 17p as well as copy number losses at chromosomes 3q, 6q, 9, 10, 13, 17p, and 18q have been detected by numerous groups, but definitive oncogenes or tumour suppressor genes remain elusive with respect to many loci. In this paper, we examine studies of the genetics of osteosarcoma to comprehensively describe the heterogeneity and complexity of this cancer.
RESUMEN
Several quantitative diagnostic techniques are available to estimate gastrointestinal parasite counts in the feces of ruminants. Comparing egg and oocyst magnitudes in naturally infected samples has been a recommended approach to rank fecal techniques. In this study, we compared the Mini-FLOTAC (sensitivity of 5 eggs per gram (EPG)/oocysts per gram (OPG)) and different averaged replicates of the modified McMaster techniques (sensitivity of 33.33 EPG/OPG) in 387 fecal samples from 10 herds of naturally infected North American bison in the Central Great Plains region of the USA. Both techniques were performed with fecal slurries homogenized in a fill-FLOTAC device. In the study population, prevalence of strongyle eggs, Eimeria spp. oocysts, Moniezia spp. eggs and Trichuris spp. eggs was 81.4%, 73.9%, 7.5%, and 3.1%, respectively. Counts of strongyle eggs and Eimeria spp. oocysts obtained from 1 to 3 averaged technical replicates of the modified McMaster technique were compared to a single replicate of the Mini-FLOTAC. Correlation between the two techniques increased with an increase in the number of averaged technical replicates of the modified McMaster technique used to calculate EGP/OPG. The correlation for Moniezia spp. EPG when averaged triplicates of the modified McMaster technique were compared to a single replicate of the Mini-FLOTAC count was high; however, the correlation for Trichuris spp. eggs was low. Additionally, we used averaged counts from both techniques to show the overdispersion of parasites in bison herds.
RESUMEN
HIV-1 accessory proteins Nef and Vpu enhance viral pathogenesis through partially overlapping immune evasion activities. Attenuated Nef or Vpu functions have been reported in individuals who display slower disease progression, but few studies have assessed the relative impact of these proteins in non-B HIV-1 subtypes or examined paired proteins from the same individuals. Here, we examined the sequence and function of matched Nef and Vpu clones isolated from 29 long-term survivors (LTS) from Rwanda living with HIV-1 subtype A and compared our results to those of 104 Nef and 62 Vpu clones isolated from individuals living with chronic untreated HIV-1 subtype A from the same geographic area. Nef and vpu coding regions were amplified from plasma HIV RNA and cloned. The function of one intact, phylogenetically-validated Nef and Vpu clone per individual was then quantified by flow cytometry following transient expression in an immortalized CD4+ T-cell line. We measured the ability of each Nef clone to downregulate CD4 and HLA class I, and of each Vpu clone to downregulate CD4 and Tetherin, from the cell surface. Results were normalized to reference clones (Nef-SF2 and Vpu-NL4.3). We observed that Nef-mediated CD4 and HLA downregulation functions were lower in LTS compared to the control cohort (Mann-Whitney p=0.03 and p<0.0001, respectively). Moreover, we found a positive correlation between Nef-mediated CD4 downregulation function and plasma viral load in LTS and controls (Spearman ρ= 0.59, p=0.03 and ρ=0.30, p=0.005, respectively). In contrast, Vpu-mediated functions were similar between groups and did not correlate with clinical markers. Further analyses identified polymorphisms at Nef codon 184 and Vpu codons 60-62 that were associated with function, which were confirmed through mutagenesis. Overall, our results support attenuated function of Nef, but not Vpu, as a contributor to slower disease progression in this cohort of long-term survivors with HIV-1 subtype A.
RESUMEN
Determination of the prevalence of accumulated antiretroviral drug resistance among persons infected with human immunodeficiency virus (HIV) is complicated by the lack of routine measurement in clinical care. By using data from 8 clinic-based cohorts from the North American AIDS Cohort Collaboration on Research and Design, drug-resistance mutations from those with genotype tests were determined and scored using the Genotypic Resistance Interpretation Algorithm developed at Stanford University. For each year from 2000 through 2005, the prevalence was calculated using data from the tested subset, assumptions that incorporated clinical knowledge, and multiple imputation methods to yield a complete data set. A total of 9,289 patients contributed data to the analysis; 3,959 had at least 1 viral load above 1,000 copies/mL, of whom 2,962 (75%) had undergone at least 1 genotype test. Using these methods, the authors estimated that the prevalence of accumulated resistance to 2 or more antiretroviral drug classes had increased from 14% in 2000 to 17% in 2005 (P < 0.001). In contrast, the prevalence of resistance in the tested subset declined from 57% to 36% for 2 or more classes. The authors' use of clinical knowledge and multiple imputation methods revealed trends in HIV drug resistance among patients in care that were markedly different from those observed using only data from patients who had undergone genotype tests.
Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Farmacorresistencia Viral Múltiple , Infecciones por VIH/tratamiento farmacológico , VIH-1/efectos de los fármacos , Medición de Riesgo/estadística & datos numéricos , Adulto , Femenino , Estudios de Seguimiento , Genotipo , Infecciones por VIH/epidemiología , Infecciones por VIH/virología , VIH-1/genética , Humanos , Masculino , Persona de Mediana Edad , Mutación , América del Norte/epidemiología , Prevalencia , ARN Viral/genética , Estudios Retrospectivos , Factores de TiempoRESUMEN
BACKGROUND: Hepatitis C virus (HCV) genotype (GT) has become an important measure in the diagnosis and monitoring of HCV infection treatment. In the United States (U.S.) HCV GT 1 is reported as the most common infecting GT among chronically infected patients. In Europe, however, recent studies have suggested that the epidemiology of HCV GTs is changing. METHODS: We assessed HCV GT distribution in 460 patients from three HCV-infected high risk populations in San Francisco, and examined patterns by birth cohort to assess temporal trends. Multiple logistic regression was used to assess factors independently associated with GT 1 infection compared to other GTs (2, 3, and 4). RESULTS: Overall, GT 1 was predominant (72.4%), however younger injection drug users (IDU) had a lower proportion of GT 1 infections (54.7%) compared to older IDU and HIV-infected patients (80.5% and 76.6%, respectively). Analysis by birth cohort showed increasing proportions of non-GT 1 infections associated with year of birth: birth before 1970 was independently associated with higher adjusted odds of GT 1: AOR 2.03 (95% CI: 1.23, 3.34). African-Americans as compared to whites also had higher adjusted odds of GT 1 infection (AOR: 3.37; 95% CI: 1.89, 5.99). CONCLUSIONS: Although, HCV GT 1 remains the most prevalent GT, especially among older groups, changes in GT distribution could have significant implications for how HCV might be controlled on a population level and treated on an individual level.
Asunto(s)
Hepacivirus/clasificación , Hepacivirus/genética , Hepatitis C Crónica/epidemiología , Hepatitis C Crónica/virología , Adulto , Estudios de Cohortes , Femenino , Genotipo , Hepacivirus/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Modelos Estadísticos , San Francisco/epidemiología , Factores de Tiempo , Población BlancaRESUMEN
This article provides insights into the experiences of families with a child with congenital heart disease. These are clarified by descriptions of the most common defects and their surgery. The way in which the condition affects each family, from pregnancy onwards, is unique to them, but informed children's nurses can do much to help.
Asunto(s)
Familia , Cardiopatías Congénitas/psicología , Adulto , Niño , Cardiopatías Congénitas/cirugía , HumanosRESUMEN
BACKGROUND: Input from practice leaders will improve how doctor of nursing practice (DNP) education is meeting the needs of the employer and improving patient outcomes. PURPOSE: This article describes the expectations practice leaders have of new DNP graduates' ability to contribute to quality improvement (QI) efforts within health care organizations. METHODS: A survey of practice leaders and QI experts investigated the importance and use of QI knowledge and skills. Practice leaders were also asked about the expectations of DNP graduates at the time of hire. RESULTS: The results of this study support the need for nurses pursuing a DNP in advanced nursing practice to have education and training beyond their area of specialization, specifically in QI methods and tools. CONCLUSIONS: Faculty need to provide DNP students education that includes concepts in QI and leadership to meet the expectations of future employers and the needs of a complex and changing health care system.
Asunto(s)
Educación de Postgrado en Enfermería , Enfermeras y Enfermeros , Estudiantes de Enfermería , Humanos , Motivación , Investigación en Educación de Enfermería , Mejoramiento de la CalidadRESUMEN
BACKGROUND: Quality improvement (QI) projects comprise the majority of University of Maryland School of Nursing (UMSON) Doctor of Nursing Practice (DNP) projects. METHODS: An online survey was completed by 51% (n = 38) of faculty, who teach or mentor DNP students, and was analyzed using quantitative and descriptive methods. RESULTS: Faculty were somewhat or not familiar with developing a QI charter 68.4%, human error theory and error proofing 63.2%, driver diagrams 60.5%, characteristics of high-reliability organizations 60.5%, and Standards for Quality Improvement Reporting Excellence (SQUIRE) guidelines 55.3%. The faculty were most interested in learning more about (n = 97 responses) were human error theory and error proofing (28.9%), SQUIRE guidelines (26.3%), statistical process control (21.1%), and implementation strategies and tactics (21.1%). The most commonly identified challenges included identifying QI projects (24%), project time constraints (16%), keeping up-to-date on QI concepts, methods, and tools (12%), and balancing professional workload (10%). CONCLUSIONS: Gaps in self-reported QI knowledge indicate there is a need for further development of DNP and PhD prepared faculty at the UMSON.
RESUMEN
BACKGROUND: Human osteosarcoma is the most common pediatric bone tumor. There is limited understanding of the molecular mechanisms underlying osteosarcoma oncogenesis, and a lack of good diagnostic as well as prognostic clinical markers for this disease. Recent discoveries have highlighted a potential role of a number of genes including: RECQL4, DOCK5, SPP1, RUNX2, RB1, CDKN1A, P53, IBSP, LSAMP, MYC, TNFRSF1B, BMP2, HISTH2BE, FOS, CCNB1, and CDC5L. METHODS: Our objective was to assess relative expression levels of these 16 genes as potential biomarkers of osteosarcoma oncogenesis and chemotherapy response in human tumors. We performed quantitative expression analysis in a panel of 22 human osteosarcoma tumors with differential response to chemotherapy, and 5 normal human osteoblasts. RESULTS: RECQL4, SPP1, RUNX2, and IBSP were significantly overexpressed, and DOCK5, CDKN1A, RB1, P53, and LSAMP showed significant loss of expression relative to normal osteoblasts. In addition to being overexpressed in osteosarcoma tumor samples relative to normal osteoblasts, RUNX2 was the only gene of the 16 to show significant overexpression in tumors that had a poor response to chemotherapy relative to good responders. CONCLUSION: These data underscore the loss of tumor suppressive pathways and activation of specific oncogenic mechanisms associated with osteosarcoma oncogenesis, while drawing attention to the role of RUNX2 expression as a potential biomarker of chemotherapy failure in osteosarcoma.