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1.
Am J Trop Med Hyg ; 110(6): 1178-1179, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38653230

RESUMEN

We report strong Zika virus (ZIKV) neutralizing antibody responses in African green monkeys (Chlorocebus sabaeus) up to 1,427 days after ZIKV exposure via the subcutaneous, intravaginal, or intrarectal routes. Our results suggest that immunocompetent African green monkeys previously infected with ZIKV are likely protected from reinfection for years, possibly life, and would not contribute to virus amplification during ZIKV epizootics.


Asunto(s)
Anticuerpos Neutralizantes , Anticuerpos Antivirales , Infección por el Virus Zika , Virus Zika , Animales , Chlorocebus aethiops , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/inmunología , Virus Zika/inmunología , Infección por el Virus Zika/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , Femenino
2.
Am J Trop Med Hyg ; 104(3): 1093-1095, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33534737

RESUMEN

Following vaccination with the live attenuated, recombinant vesicular stomatitis virus Indiana serotype Ebola virus (rVSV-EBOV) vaccine, persons may exhibit a transient vaccine-associated viremia. To investigate the potential for Old World sand flies to transmit this vaccine following feeding on a viremic person, we fed laboratory-reared Phlebotomus papatasi an artificial blood meal containing 7.2 log10 plaque-forming units of rVSV-EBOV. Replication or dissemination was not detected in the body or legs of any P. papatasi collected at seven (n = 75) or 15 (n = 75) days post-feed. These results indicate a low potential for rVSV-EBOV to replicate and disseminate in P. papatasi, a species whose geographic distribution ranges from Morocco to southwest Asia and as far north as southern Europe.


Asunto(s)
Anticuerpos Antivirales/sangre , Transmisión de Enfermedad Infecciosa , Vacunas contra el Virus del Ébola/inmunología , Ebolavirus/efectos de los fármacos , Fiebre Hemorrágica Ebola/prevención & control , Fiebre Hemorrágica Ebola/transmisión , Phlebotomus/virología , Animales , Humanos
3.
Cell Host Microbe ; 28(5): 646-659, 2020 11 11.
Artículo en Inglés | MEDLINE | ID: mdl-33152279

RESUMEN

The Preclinical Working Group of Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV), a public-private partnership spearheaded by the National Institutes of Health, has been charged with identifying, prioritizing, and communicating SARS-CoV-2 preclinical resources. Reviewing SARS-CoV-2 animal model data facilitates standardization and harmonization and informs knowledge gaps and prioritization of limited resources. To date, mouse, hamster, ferret, guinea pig, and non-human primates have been investigated. Several species are permissive for SARS-CoV-2 replication, often exhibiting mild disease with resolution, reflecting most human COVID-19 cases. More severe disease develops in a few models, some associated with advanced age, a risk factor for human disease. This review provides a snapshot that recommends the suitability of models for testing vaccines and therapeutics, which may evolve as our understanding of COVID-19 disease biology improves. COVID-19 is a complex disease, and individual models recapitulate certain aspects of disease; therefore, the coordination and assessment of animal models is imperative.


Asunto(s)
Infecciones por Coronavirus , Coronavirus , Pandemias , Neumonía Viral , Vacunas , Animales , Betacoronavirus , COVID-19 , Infecciones por Coronavirus/epidemiología , Cricetinae , Cobayas , Humanos , Ratones , Pandemias/prevención & control , SARS-CoV-2
4.
PLoS Negl Trop Dis ; 14(6): e0008107, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32569276

RESUMEN

Mosquito-borne and sexual transmission of Zika virus (ZIKV), a TORCH pathogen, recently initiated a series of large epidemics throughout the Tropics. Animal models are necessary to determine transmission risk and study pathogenesis, as well screen antivirals and vaccine candidates. In this study, we modeled mosquito and sexual transmission of ZIKV in the African green monkey (AGM). Following subcutaneous, intravaginal or intrarectal inoculation of AGMs with ZIKV, we determined the transmission potential and infection dynamics of the virus. AGMs inoculated by all three transmission routes exhibited viremia and viral shedding followed by strong virus neutralizing antibody responses, in the absence of clinical illness. All four of the subcutaneously inoculated AGMs became infected (mean peak viremia: 2.9 log10 PFU/mL, mean duration: 4.3 days) and vRNA was detected in their oral swabs, with infectious virus being detected in a subset of these specimens. Although all four of the intravaginally inoculated AGMs developed virus neutralizing antibody responses, only three had detectable viremia (mean peak viremia: 4.0 log10 PFU/mL, mean duration: 3.0 days). These three AGMs also had vRNA and infectious virus detected in both oral and vaginal swabs. Two of the four intrarectally inoculated AGMs became infected (mean peak viremia: 3.8 log10 PFU/mL, mean duration: 3.5 days). vRNA was detected in oral swabs collected from both of these infected AGMs, and infectious virus was detected in an oral swab from one of these AGMs. Notably, vRNA and infectious virus were detected in vaginal swabs collected from the infected female AGM (peak viral load: 7.5 log10 copies/mL, peak titer: 3.8 log10 PFU/mL, range of detection: 5-21 days post infection). Abnormal clinical chemistry and hematology results were detected and acute lymphadenopathy was observed in some AGMs. Infection dynamics in all three AGM ZIKV models are similar to those reported in the majority of human ZIKV infections. Our results indicate that the AGM can be used as a surrogate to model mosquito or sexual ZIKV transmission and infection. Furthermore, our results suggest that AGMs are likely involved in the enzootic maintenance and amplification cycle of ZIKV.


Asunto(s)
Modelos Animales de Enfermedad , Transmisión de Enfermedad Infecciosa , Enfermedades Virales de Transmisión Sexual/transmisión , Enfermedades Transmitidas por Vectores/transmisión , Infección por el Virus Zika/transmisión , Animales , Chlorocebus aethiops , Culicidae , Femenino , Masculino
5.
PLoS Pathog ; 15(12): e1008157, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31790515

RESUMEN

There are no FDA licensed vaccines or therapeutics for Venezuelan equine encephalitis virus (VEEV) which causes a debilitating acute febrile illness in humans that can progress to encephalitis. Previous studies demonstrated that murine and macaque monoclonal antibodies (mAbs) provide prophylactic and therapeutic efficacy against VEEV peripheral and aerosol challenge in mice. Additionally, humanized versions of two neutralizing mAbs specific for the E2 glycoprotein, 1A3B-7 and 1A4A-1, administered singly protected mice against aerosolized VEEV. However, no studies have demonstrated protection in nonhuman primate (NHP) models of VEEV infection. Here, we evaluated a chimeric antibody 1A3B-7 (c1A3B-7) containing mouse variable regions on a human IgG framework and a humanized antibody 1A4A-1 containing a serum half-life extension modification (Hu-1A4A-1-YTE) for their post-exposure efficacy in NHPs exposed to aerosolized VEEV. Approximately 24 hours after exposure, NHPs were administered a single bolus intravenous mAb. Control NHPs had typical biomarkers of VEEV infection including measurable viremia, fever, and lymphopenia. In contrast, c1A3B-7 treated NHPs had significant reductions in viremia and lymphopenia and on average approximately 50% reduction in fever. Although not statistically significant, Hu-1A4A-1-YTE administration did result in reductions in viremia and fever duration. Delay of treatment with c1A3B-7 to 48 hours post-exposure still provided NHPs protection from severe VEE disease through reductions in viremia and fever. These results demonstrate that post-exposure administration of c1A3B-7 protected macaques from development of severe VEE disease even when administered 48 hours following aerosol exposure and describe the first evaluations of VEEV-specific mAbs for post-exposure prophylactic use in NHPs. Viral mutations were identified in one NHP after c1A3B-7 treatment administered 24 hrs after virus exposure. This suggests that a cocktail-based therapy, or an alternative mAb against an epitope that cannot mutate without resulting in loss of viral fitness may be necessary for a highly effective therapeutic.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Neutralizantes/farmacología , Encefalomielitis Equina Venezolana/inmunología , Vacunas Virales/farmacología , Animales , Anticuerpos Monoclonales Humanizados/inmunología , Anticuerpos Neutralizantes/inmunología , Modelos Animales de Enfermedad , Encefalomielitis Equina Venezolana/prevención & control , Humanos , Macaca fascicularis , Vacunas Virales/inmunología
6.
Neuromuscul Disord ; 28(9): 757-765, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30072201

RESUMEN

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable chronic disorder of the peripheral nervous system. We retrospectively studied 30 children with a suspected diagnosis of CIDP. The diagnosis of CIDP was compared against the childhood CIDP revised diagnostic criteria 2000. Of the 30 children, five did not meet the criteria and four others met the criteria but subsequently had alternative diagnosis, leaving a total of 21 children (12 male) with CIDP as the final diagnosis. Thirteen children presented with chronic symptom-onset (>8 weeks). The majority presented with gait difficulties or pain in legs (n = 16). 12 children (57%) met the neurophysiological criteria and 18/19 (94%) met the cerebrospinal fluid criteria. Nerve biopsy was suggestive in 3/9 (33%), with magnetic resonance imaging supportive in 9/20 (45%). Twenty-one children received immuno-modulatory treatment at first presentation, of which majority (n = 19, 90%) received IVIG (immunoglobulin) monotherapy with 13 (68%) showing a good response. 8 children received second line treatment with either IVIG or steroids or plasmapharesis (PE) and 4 needed other immune-modulatory agents. During a median follow-up of 3.6 years, 9 (43%) had a monophasic course and 12 (57%) had a relapsing-remitting course. At last paediatric follow up 7 (33%) were off all treatment, 9 (43%) left with no or minimal residual disability and 6 (28%) children were walking with assistance (n = 3) or were non-ambulant (n = 3). Our review highlights challenges in the diagnosis and management of paediatric CIDP. It also confirms that certain metabolic disorders may mimic CIDP.


Asunto(s)
Marcha/fisiología , Inmunoglobulinas Intravenosas/uso terapéutico , Factores Inmunológicos/uso terapéutico , Plasmaféresis , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/diagnóstico , Adolescente , Niño , Preescolar , Progresión de la Enfermedad , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Conducción Nerviosa/fisiología , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/fisiopatología , Polirradiculoneuropatía Crónica Inflamatoria Desmielinizante/terapia , Estudios Retrospectivos , Resultado del Tratamiento
7.
Sci Rep ; 8(1): 6480, 2018 04 24.
Artículo en Inglés | MEDLINE | ID: mdl-29691416

RESUMEN

Ebola virus (EBOV) is a negative-strand RNA virus that replicates in the cytoplasm and causes an often-fatal hemorrhagic fever. EBOV, like other viruses, can reportedly encode its own microRNAs (miRNAs) to subvert host immune defenses. miRNAs are short noncoding RNAs that can regulate gene expression by hybridizing to multiple mRNAs, and viral miRNAs can enhance viral replication and infectivity by regulating host or viral genes. To date, only one EBOV miRNA has been examined in human infection. Here, we assayed mouse, rhesus macaque, cynomolgus macaque, and human samples infected with three EBOV variants for twelve computationally predicted viral miRNAs using RT-qPCR. Ten miRNAs aligned to EBOV variants and were detectable in the four species during disease with several viral miRNAs showing presymptomatic amplification in animal models. miRNA abundances in both the mouse and nonhuman primate models mirrored the human cohort, with miR-1-5p, miR-1-3p, and miR-T3-3p consistently at the highest levels. These striking similarities in the most abundant miRNAs during infection with different EBOV variants and hosts indicate that these miRNAs are potential valuable diagnostic markers and key effectors of EBOV pathogenesis.


Asunto(s)
Ebolavirus/genética , Fiebre Hemorrágica Ebola/genética , MicroARNs/genética , Animales , Expresión Génica/genética , Perfilación de la Expresión Génica/métodos , Fiebre Hemorrágica Ebola/virología , Humanos , Macaca fascicularis/genética , Macaca mulatta/genética , Ratones , ARN Mensajero/metabolismo , Replicación Viral/genética
8.
Am J Trop Med Hyg ; 98(3): 864-867, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29405107

RESUMEN

To evaluate potential immunocompetent small animal models of Zika virus (ZIKV) infection, we inoculated Syrian golden hamsters (subcutaneously or intraperitoneally) and strain 13 guinea pigs (intraperitoneally) with Senegalese ZIKV strain ArD 41525 or Philippines ZIKV strain CPC-0740. We did not detect viremia in hamsters inoculated subcutaneously with either virus strain, although some hamsters developed virus neutralizing antibodies. However, we detected statistically significant higher viremias (P = 0.0285) and a higher median neutralization titer (P = 0.0163) in hamsters inoculated intraperitoneally with strain ArD 41525 compared with strain CPC-0740. Furthermore, some hamsters inoculated with strain ArD 41525 displayed mild signs of disease. By contrast, strain 13 guinea pigs inoculated intraperitoneally with either strain did not have detectable viremias and less than half developed virus neutralizing antibodies. Our results support the use of the Syrian golden hamster intraperitoneal model to explore phenotypic variation between ZIKV strains.


Asunto(s)
Anticuerpos Neutralizantes/biosíntesis , Anticuerpos Antivirales/biosíntesis , Resistencia a la Enfermedad , Viremia/virología , Infección por el Virus Zika/virología , Virus Zika/inmunología , Animales , Modelos Animales de Enfermedad , Femenino , Cobayas , Especificidad del Huésped , Inyecciones Intraperitoneales , Inyecciones Subcutáneas , Mesocricetus , Viremia/inmunología , Virus Zika/crecimiento & desarrollo , Infección por el Virus Zika/inmunología
9.
Parasit Vectors ; 10(1): 218, 2017 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-28468673

RESUMEN

BACKGROUND: Ebola virus (EBOV) infection results in high morbidity and mortality and is primarily transmitted in communities by contact with infectious bodily fluids. While clinical and experimental evidence indicates that EBOV is transmitted via mucosal exposure, the ability of non-biting muscid flies to mechanically transmit EBOV following exposure to the face had not been assessed. RESULTS: To investigate this transmission route, house flies (Musca domestica Linnaeus) were used to deliver an EBOV/blood mixture to the ocular/nasal/oral facial mucosa of four cynomolgus macaques (Macaca fascicularis Raffles). Following exposure, macaques were monitored for evidence of infection through the conclusion of the study, days 57 and 58. We found no evidence of systemic infection in any of the exposed macaques. CONCLUSIONS: The results of this study indicate that there is a low potential for the mechanical transmission of EBOV via house flies - the conditions in this study were not sufficient to initiate infection.


Asunto(s)
Ebolavirus/aislamiento & purificación , Fiebre Hemorrágica Ebola/transmisión , Moscas Domésticas/virología , Insectos Vectores/virología , Animales , Ojo/virología , Cara/virología , Heces/virología , Fiebre Hemorrágica Ebola/sangre , Fiebre Hemorrágica Ebola/virología , Macaca fascicularis , Mucosa Bucal/virología , Membrana Mucosa/virología , Nariz/virología
10.
Emerg Infect Dis ; 23(8): 1274-1281, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28548637

RESUMEN

Unprotected sexual intercourse between persons residing in or traveling from regions with Zika virus transmission is a risk factor for infection. To model risk for infection after sexual intercourse, we inoculated rhesus and cynomolgus macaques with Zika virus by intravaginal or intrarectal routes. In macaques inoculated intravaginally, we detected viremia and virus RNA in 50% of macaques, followed by seroconversion. In macaques inoculated intrarectally, we detected viremia, virus RNA, or both, in 100% of both species, followed by seroconversion. The magnitude and duration of infectious virus in the blood of macaques suggest humans infected with Zika virus through sexual transmission will likely generate viremias sufficient to infect competent mosquito vectors. Our results indicate that transmission of Zika virus by sexual intercourse might serve as a virus maintenance mechanism in the absence of mosquito-to-human transmission and could increase the probability of establishment and spread of Zika virus in regions where this virus is not present.


Asunto(s)
Macaca fascicularis , Macaca mulatta , Infección por el Virus Zika/virología , Virus Zika/fisiología , Animales , Femenino , Masculino , Vagina , Replicación Viral , Esparcimiento de Virus , Infección por el Virus Zika/transmisión
11.
Sci Rep ; 6: 24496, 2016 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-27098369

RESUMEN

Early detection of Ebola virus (EBOV) infection is essential to halting transmission and adjudicating appropriate treatment. However, current methods rely on viral identification, and this approach can misdiagnose presymptomatic and asymptomatic individuals. In contrast, disease-driven alterations in the host transcriptome can be exploited for pathogen-specific diagnostic biomarkers. Here, we present for the first time EBOV-induced changes in circulating miRNA populations of nonhuman primates (NHPs) and humans. We retrospectively profiled longitudinally-collected plasma samples from rhesus macaques challenged via intramuscular and aerosol routes and found 36 miRNAs differentially present in both groups. Comparison of miRNA abundances to viral loads uncovered 15 highly correlated miRNAs common to EBOV-infected NHPs and humans. As proof of principle, we developed an eight-miRNA classifier that correctly categorized infection status in 64/74 (86%) human and NHP samples. The classifier identified acute infections in 27/29 (93.1%) samples and in 6/12 (50%) presymptomatic NHPs. These findings showed applicability of NHP-derived miRNAs to a human cohort, and with additional research the resulting classifiers could impact the current capability to diagnose presymptomatic and asymptomatic EBOV infections.


Asunto(s)
Ebolavirus/fisiología , Fiebre Hemorrágica Ebola/genética , Fiebre Hemorrágica Ebola/virología , Interacciones Huésped-Patógeno/genética , MicroARNs/genética , Adolescente , Adulto , Animales , Biomarcadores , Análisis por Conglomerados , Biología Computacional/métodos , Modelos Animales de Enfermedad , Femenino , Perfilación de la Expresión Génica , Fiebre Hemorrágica Ebola/sangre , Fiebre Hemorrágica Ebola/diagnóstico , Humanos , Macaca mulatta , Masculino , MicroARNs/sangre , Persona de Mediana Edad , Carga Viral , Adulto Joven
12.
Viruses ; 7(12): 6739-54, 2015 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-26703716

RESUMEN

Recent experimentation with the variants of the Ebola virus that differ in the glycoprotein's poly-uridine site, which dictates the form of glycoprotein produced through a transcriptional stutter, has resulted in questions regarding the pathogenicity and lethality of the stocks used to develop products currently undergoing human clinical trials to combat the disease. In order to address these concerns and prevent the delay of these critical research programs, we designed an experiment that permitted us to intramuscularly challenge statistically significant numbers of naïve and vaccinated cynomolgus macaques with either a 7U or 8U variant of the Ebola virus, Kikwit isolate. In naïve animals, no difference in survivorship was observed; however, there was a significant delay in the disease course between the two groups. Significant differences were also observed in time-of-fever, serum chemistry, and hematology. In vaccinated animals, there was no statistical difference in survivorship between either challenge groups, with two succumbing in the 7U group compared to 1 in the 8U challenge group. In summary, survivorship was not affected, but the Ebola virus disease course in nonhuman primates is temporally influenced by glycoprotein poly-U editing site populations.


Asunto(s)
Fiebre Hemorrágica Ebola/patología , Fiebre Hemorrágica Ebola/virología , Poli U/análisis , Proteínas del Envoltorio Viral/química , Factores de Virulencia/química , Animales , Modelos Animales de Enfermedad , Inyecciones Intramusculares , Macaca fascicularis , Análisis de Supervivencia , Proteínas del Envoltorio Viral/metabolismo , Factores de Virulencia/metabolismo
13.
Neuromuscul Disord ; 24(8): 707-12, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24951453

RESUMEN

The spectrum of RYR1 mutation associated disease encompasses congenital myopathies, exercise induced rhabdomyolysis, malignant hyperthermia susceptibility and King-Denborough syndrome. We report the clinical phenotype of two siblings who presented in infancy with hypotonia and striking fatigable ptosis. Their response to pyridostigimine was striking, but genetic screening for congenital myasthenic syndromes was negative, prompting further evaluation. Muscle MRI was abnormal with a selective pattern of involvement evocative of RYR1-related myopathy. This directed sequencing of the RYR1 gene, which revealed two heterozygous c.6721C>T (p.Arg2241X) nonsense mutations and novel c.8888T>C (p.Leu2963Pro) mutations in both siblings. These cases broaden the RYR1-related disease spectrum to include a myasthenic-like phenotype, including partial response to pyridostigimine. RYR1-related myopathy should be considered in the presence of fatigable weakness especially if muscle imaging demonstrates structural abnormalities. Single fibre electromyography can also be helpful in cases like this.


Asunto(s)
Inhibidores de la Colinesterasa/uso terapéutico , Miotonía Congénita/tratamiento farmacológico , Miotonía Congénita/genética , Bromuro de Piridostigmina/uso terapéutico , Canal Liberador de Calcio Receptor de Rianodina/genética , Biopsia , Codón sin Sentido , Femenino , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Fatiga Muscular/efectos de los fármacos , Fatiga Muscular/fisiología , Músculos/efectos de los fármacos , Músculos/patología , Músculos/fisiopatología , Miotonía Congénita/patología , Miotonía Congénita/fisiopatología , Hermanos , Resultado del Tratamiento
14.
Comp Med ; 63(3): 252-61, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23759528

RESUMEN

Previous studies have demonstrated that prior infection by various bacterial pathogens induces nonspecific resistance to subsequent infection by other gram-negative and gram-positive bacterial pathogens. In the present study, we evaluated whether underlying inflammation enhanced host resistance to inhalational Bacillus anthracis infection in New Zealand White rabbits (SPF; Bordetella- and Pasteurella-free). Accordingly, rabbits were pretreated with either the inflammagen bacterial LPS (60,000 EU/kg), a component of the outer membrane of gram-negative bacteria, or saline (vehicle). Administration of LPS resulted in brief pyrexia and a significant increase in the proinflammatory cytokine TNFα, thus confirming LPS-induced inflammation. At 24 h after LPS treatment, rabbits were exposed to aerosolized B. anthracis spores (Ames strain; approximately 300 LD50). Blood samples collected at various times after challenge were cultured. Compared with their saline-pretreated counterparts, LPS-pretreated, B. anthracis challenged rabbits exhibited delays in 2 biomarkers of B. anthracis infection-anthrax-induced pyrexia (25 h versus 66 h after challenge, respectively) and bacteremia (26 h versus 63 h, respectively)-and survived longer (41 h versus 90 h, respectively). Similar to control animals, all LPS-pretreated, B. anthracis-challenged rabbits exhibited pathology consistent with inhalational anthrax. Taken together, these results suggest that prior or underlying stimulation of the innate immune system induces transient host resistance to subsequent B. anthracis infection in SPF New Zealand white rabbits. In particular, our results emphasize the importance of using animals that are free of underlying infections to prevent confounding data in studies for inhalational anthrax characterization and medical countermeasure evaluation.


Asunto(s)
Carbunco/prevención & control , Bacillus anthracis/patogenicidad , Lipopolisacáridos/farmacología , Aerosoles , Animales , Bacillus anthracis/fisiología , Relación Dosis-Respuesta a Droga , Femenino , Dosificación Letal Mediana , Masculino , Conejos , Esporas Bacterianas
15.
Rev Sci Instrum ; 84(1): 013304, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23387639

RESUMEN

In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements of the cold neutron flux, the very low energy neutron production rate, and the UCN rates and density at the exit from the biological shield are presented and compared to Monte Carlo predictions. The cold neutron rates compare well with predictions from the Monte Carlo code MCNPX and the UCN rates agree with our custom UCN Monte Carlo code. The source is shown to perform as modeled. The maximum delivered UCN density at the exit from the biological shield is 52(9) UCN/cc with a solid deuterium volume of ~1500 cm(3).

16.
Clin Radiol ; 67(9): 840-2, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22841371

RESUMEN

AIM: To determine whether the presence of bone bars (BB) identified on anteroposterior hip radiographs are more prevalent in patients that have had a hip fracture as compared to patients without a fracture. MATERIALS AND METHODS: Ninety-two Caucasian women with a unilateral proximal femur fracture were retrospectively evaluated and randomly selected using radiology database records to comprise the investigational group. Ninety-eight age-matched Caucasian women without hip fracture were selected as a control group. Anteroposterior hip radiographs were evaluated for the presence of BBs by two musculoskeletal radiologists. Chi-square tests were used to assess whether fractures were more prevalent in patients with BB than those without BB. RESULTS: The patient population was comprised Caucasian women with a mean age of 79.8 ± 6.4 years in the control group and 79.9 ± 6.6 years in the investigational group. Regardless of the reader, BB were identified in a significantly higher percentage of women with a fracture (75 versus 39%, p < 0.001 or 53 versus 38%, p = 0.041) as compared to those without a fracture. CONCLUSION: BB are associated with hip fracture. Their presence is a trigger for requesting a dual-energy x-ray absorptiometry (DXA) examination to confirm or refute a diagnosis of low bone mineral density (BMD) and a subsequent increased risk of fracture.


Asunto(s)
Fracturas de Cadera/diagnóstico por imagen , Fracturas de Cadera/etnología , Osteoporosis Posmenopáusica/diagnóstico por imagen , Osteoporosis Posmenopáusica/etnología , Población Blanca/estadística & datos numéricos , Anciano , Densidad Ósea , Estudios de Cohortes , Comorbilidad , Femenino , Cadera/diagnóstico por imagen , Humanos , Variaciones Dependientes del Observador , Posmenopausia , Prevalencia , Radiografía , Estudios Retrospectivos , Factores de Riesgo
17.
Infect Immun ; 80(9): 3332-40, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22778104

RESUMEN

Burkholderia pseudomallei, the causative agent of melioidosis, is recognized as a serious health threat due to its involvement in septic and pulmonary infections in areas of endemicity and is recognized by the Centers for Disease Control and Prevention as a category B biothreat agent. An animal model is desirable to evaluate the pathogenesis of melioidosis and medical countermeasures. A model system that represents human melioidosis infections is essential in this process. A group of 10 rhesus macaques (RMs) and 10 African green monkeys (AGMs) was exposed to aerosolized B. pseudomallei 1026b. The first clinical signs were fever developing 24 to 40 h postexposure followed by leukocytosis resulting from a high percentage of neutrophils. Dyspnea manifested 2 to 4 days postexposure. In the AGMs, an increase in interleukin 1ß (IL-1ß), IL-6, IL-8, gamma interferon (IFN-γ), and tumor necrosis factor alpha (TNF-α) was observed. In the RMs, IL-1ß, IL-6, and TNF-α increased. All the RMs and AGMs had various degrees of bronchopneumonia, with inflammation consisting of numerous neutrophils and a moderate number of macrophages. Both the RMs and the AGMs appear to develop a melioidosis infection that closely resembles that seen in acute human melioidosis. However, for an evaluation of medical countermeasures, AGMs appear to be a more appropriate model.


Asunto(s)
Bronconeumonía/fisiopatología , Burkholderia pseudomallei/fisiología , Chlorocebus aethiops , Modelos Animales de Enfermedad , Macaca mulatta , Melioidosis/fisiopatología , Animales , Bronconeumonía/patología , Citocinas/metabolismo , Pulmón/patología , Masculino , Melioidosis/patología
18.
Phys Rev Lett ; 108(12): 122002, 2012 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-22540573

RESUMEN

The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the Δ0 resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant d(Δ)- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d(Δ)- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A(γ)-=-5.2 to +5.2 ppm. The measurement performed in this work leads to A(γ)-=-0.36±1.06±0.37±0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V(ud)/V(us). The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form factors using PV electron scattering.

19.
Health Technol Assess ; 16(22): 1-410, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22551803

RESUMEN

BACKGROUND: Chronic myeloid leukaemia (CML) is a form of cancer affecting the blood, characterised by excessive proliferation of white blood cells in the bone marrow and circulating blood. In the UK, an estimated 560 new cases of CML are diagnosed each year. OBJECTIVES: The purpose of this study was to assess the clinical effectiveness and cost-effectiveness of dasatinib and nilotinib in the treatment of people with imatinib-resistant (ImR) and imatinib-intolerant (ImI) CML. A systematic review of the clinical effectiveness literature, a review of manufacturer submissions and a critique and exploration of manufacturer submissions for accelerated phase and blast crisis CML were carried out and a decision-analytic model was developed to estimate the cost-effectiveness of dasatinib and nilotinib in chronic phase CML. SYSTEMATIC REVIEW METHODS: Key databases were searched for relevant studies from their inception to June 2009 [MEDLINE (including MEDLINE In-Process & Other Non-Indexed Citations), EMBASE, (ISI Web of Science) Conference Proceedings Citation Index and four others]. One reviewer assessed titles and abstracts of studies identified by the search strategy, with a sample checked by a second reviewer. The full text of relevant papers was obtained and screened against the full inclusion criteria independently by two reviewers. Data from included studies were extracted by one reviewer and checked by a second. Clinical effectiveness studies were synthesised through narrative review. ECONOMIC EVALUATION METHODS: Cost-effectiveness analyses reported in manufacturer submissions to the National Institute of Health and Clinical Excellence were critically appraised and summarised narratively. In addition, the models for accelerated phase and blast crisis underwent a more detailed critique and exploration. Two separate decision-analytic models were developed for chronic phase CML, one simulating a cohort of individuals who have shown or developed resistance to normal dose imatinib and one representing individuals who have been unable to continue imatinib treatment owing to adverse events. One-way, multiway and probabilistic sensitivity analyses were performed to explore structural and parameter uncertainty. RESULTS: Fifteen studies were included in the systematic review. Chronic phase: effectiveness data were limited but dasatinib and nilotinib appeared efficacious in terms of obtaining cytogenetic response and haematological response in both ImR and ImI populations. In terms of cost-effectiveness, it was extremely difficult to reach any conclusions regarding either agent in the ImR population. All three models (Novartis, PenTAG and Bristol-Myers Squibb) were seriously flawed in one way or another, as a consequence of the paucity of data appropriate to construct robust decision-analytic models. Accelerated and blast crisis: all available data originated from observational single-arm studies and there were considerable and potentially important differences in baseline characteristics which seriously undermined any process for making meaningful comparisons between treatments. Owing to a lack of available clinical data, de novo models of accelerated phase and blast crisis have not been developed. The economic evaluations carried out by the manufacturers of nilotinib and dasatinib were seriously undermined by the absence of evidence on high-dose imatinib in these populations. LIMITATIONS: The study has been necessarily constrained by the paucity of available clinical data, the differences in definitions used in the studies and the subsequent impossibility of undertaking a meaningful cost-effectiveness analyses to inform all policy questions. CONCLUSIONS: Dasatinib and nilotinib appeared efficacious in terms of obtaining cytogenetic and haematological responses in both ImR and ImI populations. It was difficult to reach any cost-effectiveness conclusions as a consequence of the paucity of the data. Future research should include a three-way, double-blind, randomised clinical trial of dasatinib, nilotinib and high-dose imatinib.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirimidinas/uso terapéutico , Tiazoles/uso terapéutico , Benzamidas , Crisis Blástica/tratamiento farmacológico , Ensayos Clínicos como Asunto , Análisis Costo-Beneficio , Dasatinib , Técnicas de Apoyo para la Decisión , Progresión de la Enfermedad , Resistencia a Antineoplásicos , Costos de la Atención en Salud/estadística & datos numéricos , Humanos , Mesilato de Imatinib , Incidencia , Leucemia Mieloide de Fase Acelerada/tratamiento farmacológico , Leucemia Mieloide de Fase Crónica/tratamiento farmacológico , Modelos Económicos , Piperazinas/farmacología , Piperazinas/uso terapéutico , Pronóstico , Inhibidores de Proteínas Quinasas/economía , Pirimidinas/economía , Pirimidinas/farmacología , Calidad de Vida , Tiazoles/economía
20.
Ann R Coll Surg Engl ; 93(6): e96-8, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21929898

RESUMEN

A delayed, metachronous presentation of bilateral adrenal metastases following colorectal cancer has never previously been reported. We describe the case of a 68-year-old man who underwent curative surgery and adjuvant chemotherapy for a locally invasive sigmoid adenocarcinoma, only to be diagnosed with metachronous bilateral adrenal metastasis necessitating further resection and chemotherapy. We discuss the literature surrounding this pathology and highlight the importance of continual, vigilant radiological surveillance of the adrenal glands after curative treatment of colorectal carcinoma with or without subsequent adrenal metastasis.


Asunto(s)
Adenocarcinoma/secundario , Neoplasias de las Glándulas Suprarrenales/secundario , Neoplasias del Colon Sigmoide/terapia , Adenocarcinoma/terapia , Anciano , Quimioterapia Adyuvante , Humanos , Masculino , Tomografía de Emisión de Positrones
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