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1.
JAMA ; 331(21): 1860-1862, 2024 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-38709541

RESUMEN

This study examines substances identified during testing of counterfeit prescription pills seized by law enforcement in Rhode Island from 2017 to 2022.


Asunto(s)
Medicamentos Falsificados , Aplicación de la Ley , Medicamentos bajo Prescripción , Humanos , Estados Unidos
3.
Science ; 378(6619): 560-565, 2022 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-36264825

RESUMEN

Monkeypox is a viral zoonotic disease endemic in Central and West Africa. In May 2022, dozens of non-endemic countries reported hundreds of monkeypox cases, most with no epidemiological link to Africa. We identified two lineages of monkeypox virus (MPXV) among two 2021 and seven 2022 US monkeypox cases: the major 2022 outbreak variant called B.1 and a minor contemporaneously sampled variant called A.2. Analyses of mutations among these two variants revealed an extreme preference for GA-to-AA mutations indicative of human APOBEC3 cytosine deaminase activity among Clade IIb MPXV (previously West African, Nigeria) sampled since 2017. Such mutations were not enriched within other MPXV clades. These findings suggest that APOBEC3 editing may be a recurrent and a dominant driver of MPXV evolution within the current outbreak.


Asunto(s)
Desaminasas APOBEC , Interacciones Huésped-Patógeno , Monkeypox virus , Mpox , Edición de ARN , Humanos , Mpox/enzimología , Mpox/virología , Monkeypox virus/genética , Monkeypox virus/aislamiento & purificación , Nigeria/epidemiología , Estados Unidos/epidemiología , Mutación , Evolución Molecular , Desaminasas APOBEC/metabolismo , Adenosina/genética , Citidina/genética
4.
MMWR Morb Mortal Wkly Rep ; 71(23): 764-769, 2022 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-35679181

RESUMEN

On May 17, 2022, the Massachusetts Department of Public Health (MDPH) Laboratory Response Network (LRN) laboratory confirmed the presence of orthopoxvirus DNA via real-time polymerase chain reaction (PCR) from lesion swabs obtained from a Massachusetts resident. Orthopoxviruses include Monkeypox virus, the causative agent of monkeypox. Subsequent real-time PCR testing at CDC on May 18 confirmed that the patient was infected with the West African clade of Monkeypox virus. Since then, confirmed cases* have been reported by nine states. In addition, 28 countries and territories,† none of which has endemic monkeypox, have reported laboratory-confirmed cases. On May 17, CDC, in coordination with state and local jurisdictions, initiated an emergency response to identify, monitor, and investigate additional monkeypox cases in the United States. This response has included releasing a Health Alert Network (HAN) Health Advisory, developing interim public health and clinical recommendations, releasing guidance for LRN testing, hosting clinician and public health partner outreach calls, disseminating health communication messages to the public, developing protocols for use and release of medical countermeasures, and facilitating delivery of vaccine postexposure prophylaxis (PEP) and antivirals that have been stockpiled by the U.S. government for preparedness and response purposes. On May 19, a call center was established to provide guidance to states for the evaluation of possible cases of monkeypox, including recommendations for clinical diagnosis and orthopoxvirus testing. The call center also gathers information about possible cases to identify interjurisdictional linkages. As of May 31, this investigation has identified 17§ cases in the United States; most cases (16) were diagnosed in persons who identify as gay, bisexual, or men who have sex with men (MSM). Ongoing investigation suggests person-to-person community transmission, and CDC urges health departments, clinicians, and the public to remain vigilant, institute appropriate infection prevention and control measures, and notify public health authorities of suspected cases to reduce disease spread. Public health authorities are identifying cases and conducting investigations to determine possible sources and prevent further spread. This activity was reviewed by CDC and conducted consistent with applicable federal law and CDC policy.¶.


Asunto(s)
Malaria , Mpox , Minorías Sexuales y de Género , Brotes de Enfermedades , Homosexualidad Masculina , Humanos , Malaria/diagnóstico , Masculino , Mpox/diagnóstico , Mpox/epidemiología , Vigilancia de la Población , Viaje , Estados Unidos/epidemiología
5.
Cell Rep Med ; 3(4): 100583, 2022 04 19.
Artículo en Inglés | MEDLINE | ID: mdl-35480627

RESUMEN

The SARS-CoV-2 Delta variant rose to dominance in mid-2021, likely propelled by an estimated 40%-80% increased transmissibility over Alpha. To investigate if this ostensible difference in transmissibility is uniform across populations, we partner with public health programs from all six states in New England in the United States. We compare logistic growth rates during each variant's respective emergence period, finding that Delta emerged 1.37-2.63 times faster than Alpha (range across states). We compute variant-specific effective reproductive numbers, estimating that Delta is 63%-167% more transmissible than Alpha (range across states). Finally, we estimate that Delta infections generate on average 6.2 (95% CI 3.1-10.9) times more viral RNA copies per milliliter than Alpha infections during their respective emergence. Overall, our evidence suggests that Delta's enhanced transmissibility can be attributed to its innate ability to increase infectiousness, but its epidemiological dynamics may vary depending on underlying population attributes and sequencing data availability.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiología , Humanos , New England/epidemiología , Salud Pública , SARS-CoV-2/genética
6.
Nat Med ; 28(5): 1083-1094, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35130561

RESUMEN

The coronavirus disease 2019 (COVID-19) pandemic has demonstrated a clear need for high-throughput, multiplexed and sensitive assays for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory viruses and their emerging variants. Here, we present a cost-effective virus and variant detection platform, called microfluidic Combinatorial Arrayed Reactions for Multiplexed Evaluation of Nucleic acids (mCARMEN), which combines CRISPR-based diagnostics and microfluidics with a streamlined workflow for clinical use. We developed the mCARMEN respiratory virus panel to test for up to 21 viruses, including SARS-CoV-2, other coronaviruses and both influenza strains, and demonstrated its diagnostic-grade performance on 525 patient specimens in an academic setting and 166 specimens in a clinical setting. We further developed an mCARMEN panel to enable the identification of 6 SARS-CoV-2 variant lineages, including Delta and Omicron, and evaluated it on 2,088 patient specimens with near-perfect concordance to sequencing-based variant classification. Lastly, we implemented a combined Cas13 and Cas12 approach that enables quantitative measurement of SARS-CoV-2 and influenza A viral copies in samples. The mCARMEN platform enables high-throughput surveillance of multiple viruses and variants simultaneously, enabling rapid detection of SARS-CoV-2 variants.


Asunto(s)
COVID-19 , Gripe Humana , COVID-19/diagnóstico , Humanos , Microfluídica , SARS-CoV-2/genética
7.
medRxiv ; 2021 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-34642698

RESUMEN

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant quickly rose to dominance in mid-2021, displacing other variants, including Alpha. Studies using data from the United Kingdom and India estimated that Delta was 40-80% more transmissible than Alpha, allowing Delta to become the globally dominant variant. However, it was unclear if the ostensible difference in relative transmissibility was due mostly to innate properties of Delta's infectiousness or differences in the study populations. To investigate, we formed a partnership with SARS-CoV-2 genomic surveillance programs from all six New England US states. By comparing logistic growth rates, we found that Delta emerged 37-163% faster than Alpha in early 2021 (37% Massachusetts, 75% New Hampshire, 95% Maine, 98% Rhode Island, 151% Connecticut, and 163% Vermont). We next computed variant-specific effective reproductive numbers and estimated that Delta was 58-120% more transmissible than Alpha across New England (58% New Hampshire, 68% Massachusetts, 76% Connecticut, 85% Rhode Island, 98% Maine, and 120% Vermont). Finally, using RT-PCR data, we estimated that Delta infections generate on average ∼6 times more viral RNA copies per mL than Alpha infections. Overall, our evidence indicates that Delta's enhanced transmissibility could be attributed to its innate ability to increase infectiousness, but its epidemiological dynamics may vary depending on the underlying immunity and behavior of distinct populations.

8.
MMWR Morb Mortal Wkly Rep ; 70(31): 1059-1062, 2021 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-34351882

RESUMEN

During July 2021, 469 cases of COVID-19 associated with multiple summer events and large public gatherings in a town in Barnstable County, Massachusetts, were identified among Massachusetts residents; vaccination coverage among eligible Massachusetts residents was 69%. Approximately three quarters (346; 74%) of cases occurred in fully vaccinated persons (those who had completed a 2-dose course of mRNA vaccine [Pfizer-BioNTech or Moderna] or had received a single dose of Janssen [Johnson & Johnson] vaccine ≥14 days before exposure). Genomic sequencing of specimens from 133 patients identified the B.1.617.2 (Delta) variant of SARS-CoV-2, the virus that causes COVID-19, in 119 (89%) and the Delta AY.3 sublineage in one (1%). Overall, 274 (79%) vaccinated patients with breakthrough infection were symptomatic. Among five COVID-19 patients who were hospitalized, four were fully vaccinated; no deaths were reported. Real-time reverse transcription-polymerase chain reaction (RT-PCR) cycle threshold (Ct) values in specimens from 127 vaccinated persons with breakthrough cases were similar to those from 84 persons who were unvaccinated, not fully vaccinated, or whose vaccination status was unknown (median = 22.77 and 21.54, respectively). The Delta variant of SARS-CoV-2 is highly transmissible (1); vaccination is the most important strategy to prevent severe illness and death. On July 27, CDC recommended that all persons, including those who are fully vaccinated, should wear masks in indoor public settings in areas where COVID-19 transmission is high or substantial.* Findings from this investigation suggest that even jurisdictions without substantial or high COVID-19 transmission might consider expanding prevention strategies, including masking in indoor public settings regardless of vaccination status, given the potential risk of infection during attendance at large public gatherings that include travelers from many areas with differing levels of transmission.


Asunto(s)
COVID-19/epidemiología , COVID-19/transmisión , Aglomeración , Brotes de Enfermedades , Adolescente , Adulto , Anciano , Vacunas contra la COVID-19/administración & dosificación , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Massachusetts/epidemiología , Persona de Mediana Edad , Adulto Joven
9.
Emerg Infect Dis ; 27(5): 1296-1300, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33900178

RESUMEN

Zika virus diagnostic testing and laboratory research increased considerably when Zika virus began spreading through the Americas in 2015, increasing the risk for potential Zika virus exposure of laboratory workers and biomedical researchers. We report 4 cases of laboratory-associated Zika virus disease in the United States during 2016-2019. Of these, 2 were associated with needlestick injuries; for the other 2 cases, the route of transmission was undetermined. In laboratories in which work with Zika virus is performed, good laboratory biosafety practices must be implemented and practiced to reduce the risk for infection among laboratory personnel.


Asunto(s)
Infección por el Virus Zika , Virus Zika , Américas , Humanos , Laboratorios , Investigación , Estados Unidos
10.
Clin Infect Dis ; 73(9): 1693-1695, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-33704451

RESUMEN

We describe 3 instances of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission despite medical masks and eye protection, including transmission despite the source person being masked, transmission despite the exposed person being masked, and transmission despite both parties being masked. Whole genome sequencing confirmed perfect homology between source and exposed persons' viruses in all cases.


Asunto(s)
COVID-19 , SARS-CoV-2 , Atención a la Salud , Humanos , Máscaras
11.
Ann Intern Med ; 174(6): 794-802, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33556277

RESUMEN

BACKGROUND: Little is known about clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in acute care hospitals. OBJECTIVE: To describe the detection, mitigation, and analysis of a large cluster of SARS-CoV-2 infections in an acute care hospital with mature infection control policies. DESIGN: Descriptive study. SETTING: Brigham and Women's Hospital, Boston, Massachusetts. PARTICIPANTS: Patients and staff with cluster-related SARS-CoV-2 infections. INTERVENTION: Close contacts of infected patients and staff were identified and tested every 3 days, patients on affected units were preemptively isolated and repeatedly tested, affected units were cleaned, room ventilation was measured, and specimens were sent for whole-genome sequencing. A case-control study was done to compare clinical interactions, personal protective equipment use, and breakroom and workroom practices in SARS-CoV-2-positive versus negative staff. MEASUREMENTS: Description of the cluster, mitigation activities, and risk factor analysis. RESULTS: Fourteen patients and 38 staff members were included in the cluster per whole-genome sequencing and epidemiologic associations. The index case was a symptomatic patient in whom isolation was discontinued after 2 negative results on nasopharyngeal polymerase chain reaction testing. The patient subsequently infected multiple roommates and staff, who then infected others. Seven of 52 (13%) secondary infections were detected only on second or subsequent tests. Eight of 9 (89%) patients who shared rooms with potentially contagious patients became infected. Potential contributing factors included high viral loads, nebulization, and positive pressure in the index patient's room. Risk factors for transmission to staff included presence during nebulization, caring for patients with dyspnea or cough, lack of eye protection, at least 15 minutes of exposure to case patients, and interactions with SARS-CoV-2-positive staff in clinical areas. Whole-genome sequencing confirmed that 2 staff members were infected despite wearing surgical masks and eye protection. LIMITATION: Findings may not be generalizable. CONCLUSION: SARS-CoV-2 clusters can occur in hospitals despite robust infection control policies. Insights from this cluster may inform additional measures to protect patients and staff. PRIMARY FUNDING SOURCE: None.


Asunto(s)
COVID-19/epidemiología , COVID-19/transmisión , Infección Hospitalaria/epidemiología , Control de Infecciones/métodos , Transmisión de Enfermedad Infecciosa de Paciente a Profesional , Neumonía Viral/epidemiología , Neumonía Viral/transmisión , Adulto , Boston/epidemiología , Prueba de COVID-19 , Estudios de Casos y Controles , Brotes de Enfermedades , Femenino , Humanos , Masculino , Equipo de Protección Personal , Neumonía Viral/virología , Factores de Riesgo , SARS-CoV-2
12.
Science ; 371(6529)2021 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-33303686

RESUMEN

Analysis of 772 complete severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes from early in the Boston-area epidemic revealed numerous introductions of the virus, a small number of which led to most cases. The data revealed two superspreading events. One, in a skilled nursing facility, led to rapid transmission and significant mortality in this vulnerable population but little broader spread, whereas other introductions into the facility had little effect. The second, at an international business conference, produced sustained community transmission and was exported, resulting in extensive regional, national, and international spread. The two events also differed substantially in the genetic variation they generated, suggesting varying transmission dynamics in superspreading events. Our results show how genomic epidemiology can help to understand the link between individual clusters and wider community spread.


Asunto(s)
COVID-19/epidemiología , Genoma Viral , Filogenia , SARS-CoV-2/genética , Boston/epidemiología , COVID-19/transmisión , Brotes de Enfermedades , Monitoreo Epidemiológico , Humanos
13.
medRxiv ; 2020 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-32869040

RESUMEN

SARS-CoV-2 has caused a severe, ongoing outbreak of COVID-19 in Massachusetts with 111,070 confirmed cases and 8,433 deaths as of August 1, 2020. To investigate the introduction, spread, and epidemiology of COVID-19 in the Boston area, we sequenced and analyzed 772 complete SARS-CoV-2 genomes from the region, including nearly all confirmed cases within the first week of the epidemic and hundreds of cases from major outbreaks at a conference, a nursing facility, and among homeless shelter guests and staff. The data reveal over 80 introductions into the Boston area, predominantly from elsewhere in the United States and Europe. We studied two superspreading events covered by the data, events that led to very different outcomes because of the timing and populations involved. One produced rapid spread in a vulnerable population but little onward transmission, while the other was a major contributor to sustained community transmission, including outbreaks in homeless populations, and was exported to several other domestic and international sites. The same two events differed significantly in the number of new mutations seen, raising the possibility that SARS-CoV-2 superspreading might encompass disparate transmission dynamics. Our results highlight the failure of measures to prevent importation into MA early in the outbreak, underscore the role of superspreading in amplifying an outbreak in a major urban area, and lay a foundation for contact tracing informed by genetic data.

14.
J Endocr Soc ; 1(10): 1272-1286, 2017 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-29264452

RESUMEN

Enteroviral infections have been associated with the development of type 1 diabetes (T1D), a chronic inflammatory disease characterized by autoimmune destruction of insulin-producing pancreatic beta cells. Cultured human islets, including the insulin-producing beta cells, can be infected with coxsackievirus B4 (CVB4) and thus are useful for understanding cellular responses to infection. We performed quantitative mass spectrometry analysis on cultured primary human islets infected with CVB4 to identify molecules and pathways altered upon infection. Corresponding uninfected controls were included in the study for comparative protein expression analyses. Proteins were significantly and differentially regulated in human islets challenged with virus compared with their uninfected counterparts. Complementary analyses of gene transcripts in CVB4-infected primary islets over a time course validated the induction of RNA transcripts for many of the proteins that were increased in the proteomics studies. Notably, infection with CVB4 results in a considerable decrease in insulin. Genes/proteins modulated during CVB4 infection also include those involved in activation of immune responses, including type I interferon pathways linked to T1D pathogenesis and with antiviral, cell repair, and inflammatory properties. Our study applies proteomics analyses to cultured human islets challenged with virus and identifies target proteins that could be useful in T1D interventions.

15.
RNA ; 21(12): 2067-75, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26428694

RESUMEN

Influenza A virus (IAV) lacks the enzyme for adding 5' caps to its RNAs and snatches the 5' ends of host capped RNAs to prime transcription. Neither the preference of the host RNA sequences snatched nor the effect of cap-snatching on host processes is completely defined. Previous studies of influenza cap-snatching used poly(A)-selected RNAs from infected cells or relied on annotated host genes to define the snatched host RNAs, and thus lack details on many noncoding host RNAs including snRNAs, snoRNAs, and promoter-associated capped small (cs)RNAs, which are made by "paused" Pol II during transcription initiation. In this study, we used a nonbiased technique, CapSeq, to identify host and viral-capped RNAs including nonpolyadenylated RNAs in the same samples, and investigated the substrate-product correlation between the host RNAs and the viral RNAs. We demonstrated that noncoding host RNAs, particularly U1 and U2, are the preferred cap-snatching source over mRNAs or pre-mRNAs. We also found that csRNAs are highly snatched by IAV. Because the functions of csRNAs remain mostly unknown, especially in somatic cells, our finding reveals that csRNAs at least play roles in the process of IAV infection. Our findings support a model where nascent RNAs including csRNAs are the preferred targets for cap-snatching by IAV and raise questions about how IAV might use snatching preferences to modulate host-mRNA splicing and transcription.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/genética , Caperuzas de ARN/metabolismo , Secuencia de Bases , Línea Celular Tumoral , Regulación Viral de la Expresión Génica , Genes Virales , Humanos , Subtipo H1N1 del Virus de la Influenza A/metabolismo , Procesamiento Postranscripcional del ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Viral/genética , ARN Viral/metabolismo
16.
Mol Biol Evol ; 32(6): 1519-32, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25713211

RESUMEN

Influenza A virus (IAV) has a segmented genome that allows for the exchange of genome segments between different strains. This reassortment accelerates evolution by breaking linkage, helping IAV cross species barriers to potentially create highly virulent strains. Challenges associated with monitoring the process of reassortment in molecular detail have limited our understanding of its evolutionary implications. We applied a novel deep sequencing approach with quantitative analysis to assess the in vitro temporal evolution of genomic reassortment in IAV. The combination of H1N1 and H3N2 strains reproducibly generated a new H1N2 strain with the hemagglutinin and nucleoprotein segments originating from H1N1 and the remaining six segments from H3N2. By deep sequencing the entire viral genome, we monitored the evolution of reassortment, quantifying the relative abundance of all IAV genome segments from the two parent strains over time and measuring the selection coefficients of the reassorting segments. Additionally, we observed several mutations coemerging with reassortment that were not found during passaging of pure parental IAV strains. Our results demonstrate how reassortment of the segmented genome can accelerate viral evolution in IAV, potentially enabled by the emergence of a small number of individual mutations.


Asunto(s)
Alphainfluenzavirus/genética , Genoma Viral , Virus Reordenados/genética , Selección Genética , Animales , Biología Computacional , Perros , Evolución Molecular , Frecuencia de los Genes , Genotipo , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N2 del Virus de la Influenza A/genética , Subtipo H3N2 del Virus de la Influenza A/genética , Límite de Detección , Células de Riñón Canino Madin Darby , Nucleoproteínas/genética , Análisis de Secuencia de ARN
17.
Diabetes ; 64(4): 1358-69, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25392246

RESUMEN

Type 1 diabetes (T1D) is characterized by the destruction of the insulin-producing ß-cells of pancreatic islets. Genetic and environmental factors both contribute to T1D development. Viral infection with enteroviruses is a suspected trigger for T1D, but a causal role remains unproven and controversial. Studies in animals are problematic because of species-specific differences in host cell susceptibility and immune responses to candidate viral pathogens such as coxsackievirus B (CVB). In order to resolve the controversial role of viruses in human T1D, we developed a viral infection model in immunodeficient mice bearing human islet grafts. Hyperglycemia was induced in mice by specific ablation of native ß-cells. Human islets, which are naturally susceptible to CVB infection, were transplanted to restore normoglycemia. Transplanted mice were infected with CVB4 and monitored for hyperglycemia. Forty-seven percent of CVB4-infected mice developed hyperglycemia. Human islet grafts from infected mice contained viral RNA, expressed viral protein, and had reduced insulin levels compared with grafts from uninfected mice. Human-specific gene expression profiles in grafts from infected mice revealed the induction of multiple interferon-stimulated genes. Thus, human islets can become severely dysfunctional with diminished insulin production after CVB infection of ß-cells, resulting in diabetes.


Asunto(s)
Infecciones por Coxsackievirus/inmunología , Diabetes Mellitus Tipo 1/virología , Hiperglucemia/virología , Trasplante de Islotes Pancreáticos , Islotes Pancreáticos/virología , Animales , Diabetes Mellitus Tipo 1/inmunología , Enterovirus Humano B , Humanos , Hiperglucemia/inmunología , Islotes Pancreáticos/inmunología , Ratones
18.
J Virol ; 88(1): 272-81, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24155392

RESUMEN

Influenza A virus (IAV) is a major cause of morbidity and mortality throughout the world. Current antiviral therapies include oseltamivir, a neuraminidase inhibitor that prevents the release of nascent viral particles from infected cells. However, the IAV genome can evolve rapidly, and oseltamivir resistance mutations have been detected in numerous clinical samples. Using an in vitro evolution platform and whole-genome population sequencing, we investigated the population genomics of IAV during the development of oseltamivir resistance. Strain A/Brisbane/59/2007 (H1N1) was grown in Madin-Darby canine kidney cells with or without escalating concentrations of oseltamivir over serial passages. Following drug treatment, the H274Y resistance mutation fixed reproducibly within the population. The presence of the H274Y mutation in the viral population, at either a low or a high frequency, led to measurable changes in the neuraminidase inhibition assay. Surprisingly, fixation of the resistance mutation was not accompanied by alterations of viral population diversity or differentiation, and oseltamivir did not alter the selective environment. While the neighboring K248E mutation was also a target of positive selection prior to H274Y fixation, H274Y was the primary beneficial mutation in the population. In addition, once evolved, the H274Y mutation persisted after the withdrawal of the drug, even when not fixed in viral populations. We conclude that only selection of H274Y is required for oseltamivir resistance and that H274Y is not deleterious in the absence of the drug. These collective results could offer an explanation for the recent reproducible rise in oseltamivir resistance in seasonal H1N1 IAV strains in humans.


Asunto(s)
Antivirales/farmacología , Farmacorresistencia Viral/genética , Evolución Molecular , Genoma Viral , Subtipo H1N1 del Virus de la Influenza A/genética , Oseltamivir/farmacología , Animales , Línea Celular , Perros , Ensayos Analíticos de Alto Rendimiento , Técnicas In Vitro , Subtipo H1N1 del Virus de la Influenza A/crecimiento & desarrollo , Concentración 50 Inhibidora , Mutación , Ensayo de Placa Viral
19.
Emerg Infect Dis ; 18(1): 135-7, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22257471

RESUMEN

After 3 dengue cases were acquired in Key West, Florida, we conducted a serosurvey to determine the scope of the outbreak. Thirteen residents showed recent infection (infection rate 5%; 90% CI 2%-8%), demonstrating the reemergence of dengue in Florida. Increased awareness of dengue among health care providers is needed.


Asunto(s)
Dengue/epidemiología , Brotes de Enfermedades , Florida/epidemiología , Humanos , Oportunidad Relativa , Factores de Riesgo
20.
PLoS One ; 3(7): e2845, 2008 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-18665240

RESUMEN

The development of neural crest-derived pigment cells has been studied extensively as a model for cellular differentiation, disease and environmental adaptation. Neural crest-derived chromatophores in the zebrafish (Danio rerio) consist of three types: melanophores, xanthophores and iridiphores. We have identified the zebrafish mutant endzone (enz), that was isolated in a screen for mutants with neural crest development phenotypes, based on an abnormal melanophore pattern. We have found that although wild-type numbers of chromatophore precursors are generated in the first day of development and migrate normally in enz mutants, the numbers of all three chromatophore cell types that ultimately develop are reduced. Further, differentiated melanophores and xanthophores subsequently lose dendricity, and iridiphores are reduced in size. We demonstrate that enz function is required cell autonomously by melanophores and that the enz locus is located on chromosome 7. In addition, zebrafish enz appears to selectively regulate chromatophore development within the neural crest lineage since all other major derivatives develop normally. Our results suggest that enz is required relatively late in the development of all three embryonic chromatophore types and is normally necessary for terminal differentiation and the maintenance of cell size and morphology. Thus, although developmental regulation of different chromatophore sublineages in zebrafish is in part genetically distinct, enz provides an example of a common regulator of neural crest-derived chromatophore differentiation and morphology.


Asunto(s)
Diferenciación Celular , Cromatóforos/metabolismo , Melanóforos/metabolismo , Animales , Tipificación del Cuerpo , Tamaño de la Célula , Mapeo Cromosómico , Modelos Biológicos , Modelos Genéticos , Mutación , Cresta Neural/metabolismo , Fenotipo , Factores de Tiempo , Pez Cebra
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