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2.
Hortic Res ; 7(1): 71, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32377361

RESUMEN

In response to new European Union regulations, studies are underway to mitigate accumulation of toxic cadmium (Cd) in cacao (Theobroma cacao, Tc). This study advances such research with Cd isotope analyses of 19 genetically diverse cacao clones and yeast transformed to express cacao natural resistance-associated macrophage protein (NRAMP5) and heavy metal ATPases (HMAs). The plants were enriched in light Cd isotopes relative to the hydroponic solution with Δ114/110Cdtot-sol = -0.22 ± 0.08‰. Leaves show a systematic enrichment of isotopically heavy Cd relative to total plants, in accord with closed-system isotope fractionation of Δ114/110Cdseq-mob = -0.13‰, by sequestering isotopically light Cd in roots/stems and mobilisation of remaining Cd to leaves. The findings demonstrate that (i) transfer of Cd between roots and leaves is primarily unidirectional; (ii) different clones utilise similar pathways for Cd sequestration, which differ from those of other studied plants; (iii) clones differ in their efficiency of Cd sequestration. Transgenic yeast that expresses TcNRAMP5 (T. cacao natural resistance-associated macrophage gene) had isotopically lighter Cd than did cacao. This suggests that NRAMP5 transporters constitute an important pathway for uptake of Cd by cacao. Cd isotope signatures of transgenic yeast expressing HMA-family proteins suggest that they may contribute to Cd sequestration. The data are the first to record isotope fractionation induced by transporter proteins in vivo.

3.
Leuk Lymphoma ; 61(7): 1669-1677, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32268821

RESUMEN

The inexpensive, well-tolerated, immunomodulatory agent leflunomide, used extensively for the treatment of rheumatoid arthritis, has been shown to produce significant activity against multiple myeloma (MM) in pre-clinical studies. We conducted a phase 1 study (clinicaltrials.gov: NCT02509052) of single agent leflunomide in patients with relapsed/refractory MM (≥3 prior therapies). At dose levels 1 and 2 (20 and 40 mg), no dose-limiting toxicities (DLTs) were observed. At dose level 3 (60 mg), one patient experienced elevated alanine aminotransferase; an additional three patients were enrolled at this dose level without further DLTs. Overall, toxicities were infrequent and manageable. Nine out of 11 patients achieved stable disease (SD), two subjects experiencing SD for nearly one year or longer. The tolerable safety profile of leflunomide, combined with a potential disease stabilization, is motivating future studies of leflunomide, in combination with other MM drugs, or as an approach to delay progression of smoldering MM.


Asunto(s)
Mieloma Múltiple , Protocolos de Quimioterapia Combinada Antineoplásica , Reposicionamiento de Medicamentos , Humanos , Leflunamida/uso terapéutico , Mieloma Múltiple/tratamiento farmacológico
4.
Neuro Oncol ; 18(6): 849-54, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26902850

RESUMEN

BACKGROUND: Fatigue is common among glioma patients undergoing radiotherapy (RT) and impacts quality of life (QOL). We evaluated whether armodafinil, a wakefulness-promoting medication, improves fatigue in glioma patients undergoing RT. METHODS: Eligibility criteria included age ≥18 years, Karnofsky performance status ≥60, and grade 2-4 glioma undergoing RT to a total dose of 50-60 Gy. Patients were randomized 1:1 to armodafinil or placebo for 8 weeks beginning within 10 days of starting RT. Fatigue and QOL were assessed at baseline, day 22, day 43, and day 56 with the Functional Assessment of Chronic Illness Therapy - Fatigue (FACIT-F), the Functional Assessment of Cancer Therapy - General (FACT-G), the Brief Fatigue Inventory (BFI), and the Cancer Fatigue Scale (CFS). The primary aim was to detect a difference in the 42-day change in FACIT-F fatigue subscale between the 2 groups using a 2-sample Wilcoxon statistic. RESULTS: We enrolled 81 patients total (42 armodafinil and 39 placebo). Armodafinil did not significantly improve fatigue or QOL based on the 42-day change in FACIT-F fatigue subscale, FACT-G, CFS, or BFI. Further analysis suggests no difference between the arms even after accounting for the potential bias of missing data. Treatment was well tolerated with few grade 3 or 4 toxicities. CONCLUSIONS: While treatment was well-tolerated, an 8-week course of armodafinil did not improve fatigue or QOL in glioma patients undergoing RT in this pilot study. Further studies are needed to determine whether pharmacologic treatment improves fatigue in glioma patients undergoing RT.


Asunto(s)
Compuestos de Bencidrilo/uso terapéutico , Fatiga/tratamiento farmacológico , Glioma/radioterapia , Promotores de la Vigilia/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Método Doble Ciego , Fatiga/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modafinilo , Proyectos Piloto , Radioterapia/efectos adversos , Resultado del Tratamiento
5.
Neurology ; 84(3): 280-6, 2015 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-25527270

RESUMEN

OBJECTIVE: A subset of meningiomas recur after surgery and radiation therapy, but no medical therapy for recurrent meningioma has proven effective. METHODS: Pasireotide LAR is a long-acting somatostatin analog that may inhibit meningioma growth. This was a phase II trial in patients with histologically confirmed recurrent or progressive meningioma designed to evaluate whether pasireotide LAR prolongs progression-free survival at 6 months (PFS6). Patients were stratified by histology (atypical [World Health Organization grade 2] and malignant [grade 3] meningiomas in cohort A and benign [grade 3] in cohort B). RESULTS: Eighteen patients were accrued in cohort A and 16 in cohort B. Cohort A had median age 59 years, median Karnofsky performance status 80, 17 (94%) had previous radiation therapy, and 11 (61%) showed high octreotide uptake. Cohort B had median age 52 years, median Karnofsky performance status 90, 11 (69%) had previous radiation therapy, and 12 (75%) showed high octreotide uptake. There were no radiographic responses to pasireotide LAR therapy in either cohort. Twelve patients (67%) in cohort A and 13 (81%) in cohort B achieved stable disease. In cohort A, PFS6 was 17% and median PFS 15 weeks (95% confidence interval: 8-20). In cohort B, PFS6 was 50% and median PFS 26 weeks (12-43). Treatment was well tolerated. Octreotide uptake and insulin-like growth factor-1 levels did not predict outcome. Expression of somatostatin receptor 3 predicted favorable PFS and overall survival. CONCLUSIONS: Pasireotide LAR has limited activity in recurrent meningiomas. The finding that somatostatin receptor 3 is associated with favorable outcomes warrants further investigation. CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that in patients with recurrent or progressive meningioma, pasireotide LAR does not significantly increase the proportion of patients with PFS at 6 months.


Asunto(s)
Antineoplásicos Hormonales/uso terapéutico , Neoplasias Meníngeas/tratamiento farmacológico , Meningioma/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Somatostatina/análogos & derivados , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Supervivencia sin Enfermedad , Femenino , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Masculino , Persona de Mediana Edad , Receptores de Somatostatina/metabolismo , Somatostatina/uso terapéutico
6.
Neuro Oncol ; 15(7): 930-5, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23553268

RESUMEN

BACKGROUND: Among patients with glioblastoma (GBM) who progress on standard temozolomide, the optimal therapy is unknown. Resistance to temozolomide is partially mediated by O(6)-methylguanine-DNA methyltransferase (MGMT). Because MGMT may be depleted by prolonged temozolomide administration, dose-intense schedules may overcome resistance. METHODS: This was a multicenter, phase 2, single-arm study of temozolomide (75-100 mg/m(2)/day) for 21 days of each 28-day cycle. Patients had GBM in first recurrence after standard therapy. The primary end point was 6-month progression-free survival (PFS6). RESULTS: Fifty-eight participants were accrued, 3 of whom were ineligible for analysis; one withdrew before response assessment. There were 33 men (61%), with a median age of 57 years (range, 25-79 years) and a median Karnofsky performance score of 90 (range, 60-100). Of 47 patients with MGMT methylation results, 36 (65%) had methylated tumors. There were 7 (13%) partial responses, and PFS6 was only 11%. Response and PFS did not depend on MGMT status; MSH2, MLH1, or ERCC1 expression; the number of prior temozolomide cycles; or the time off temozolomide. Treatment was well tolerated, with limited grade 3 neutropenia (n = 2) or thrombocytopenia (n = 2). CONCLUSIONS: Dose-intense temozolomide on this schedule is safe in recurrent GBM. However, efficacy is marginal and predictive biomarkers are needed.


Asunto(s)
Antineoplásicos Alquilantes/uso terapéutico , Neoplasias Encefálicas/tratamiento farmacológico , Metilación de ADN/efectos de los fármacos , Dacarbazina/análogos & derivados , Glioblastoma/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adulto , Anciano , Biomarcadores de Tumor/genética , Neoplasias Encefálicas/mortalidad , Neoplasias Encefálicas/secundario , Metilasas de Modificación del ADN/genética , Enzimas Reparadoras del ADN/genética , Dacarbazina/uso terapéutico , Relación Dosis-Respuesta a Droga , Femenino , Estudios de Seguimiento , Glioblastoma/mortalidad , Glioblastoma/patología , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Homólogo 1 de la Proteína MutL , Proteína 2 Homóloga a MutS/metabolismo , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Proteínas Nucleares/metabolismo , Pronóstico , Regiones Promotoras Genéticas/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Tasa de Supervivencia , Temozolomida , Proteínas Supresoras de Tumor/genética
7.
Photochem Photobiol ; 89(1): 139-49, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-22803957

RESUMEN

Phthalocyanine photosensitizers are effective in anticancer photodynamic therapy (PDT) but suffer from limited solubility, limited cellular uptake and limited selectivity for cancer cells. To improve these characteristics, we synthesized isopropylidene-protected and partially deprotected tetra ß-glycosylated zinc (II) phthalocyanines and compared their uptake and accumulation kinetics, subcellular localization, in vitro photocytotoxicity and reactive oxygen species generation with those of disulfonated aluminum phthalocyanine. In MCF-7 cancer cells, one of the compounds, zinc phthalocyanine {4}, demonstrated 10-fold higher uptake, 5-fold greater PDT-induced cellular reactive oxygen species concentration and 2-fold greater phototoxicity than equimolar (9 µm) disulfonated aluminum phthalocyanine. Thus, isopropylidene-protected ß-glycosylation of phthalocyanines provides a simple method of improving the efficacy of PDT.


Asunto(s)
Antineoplásicos/farmacología , Indoles/farmacología , Compuestos Organometálicos/farmacología , Fármacos Fotosensibilizantes/farmacología , Alquenos/química , Antineoplásicos/síntesis química , Transporte Biológico , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Glicosilación , Humanos , Indoles/síntesis química , Isoindoles , Cinética , Luz , Células MCF-7 , Compuestos Organometálicos/síntesis química , Fotoquimioterapia , Fármacos Fotosensibilizantes/síntesis química , Especies Reactivas de Oxígeno/metabolismo , Compuestos de Zinc
8.
PLoS Negl Trop Dis ; 4(6): e710, 2010 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-20559541

RESUMEN

BACKGROUND: Infection with dengue viruses (DENV) leads to a spectrum of disease outcomes. The pathophysiology of severe versus non-severe manifestations of DENV infection may be driven by host responses, which could be reflected in the transcriptional profiles of peripheral blood immune cells. METHODOLOGY/PRINCIPAL FINDINGS: We conducted genome-wide microarray analysis of whole blood RNA from 34 DENV-infected children in Nicaragua collected on days 3-6 of illness, with different disease manifestations. Gene expression analysis identified genes that are differentially regulated between clinical subgroups. The most striking transcriptional differences were observed between dengue patients with and without shock, especially in the expression of mitochondrial ribosomal proteins associated with protein biosynthesis. In the dengue hemorrhagic fever patients, one subset of differentially expressed genes encode neutrophil-derived anti-microbial peptides associated with innate immunity. By performing a meta-analysis of our dataset in conjunction with previously published datasets, we confirmed that DENV infection in vivo is associated with large changes to protein and nucleic acid metabolism. Additionally, whereas in vitro infection leads to an increased interferon signature, this was not consistently observed from in vivo patient samples, suggesting that the interferon response in vivo is relatively transient and was no longer observed by days 3-6 of illness. CONCLUSIONS/SIGNIFICANCE: These data highlight important differences between different manifestations of severity during DENV infection as well as identify some commonalities. Compilation of larger datasets in the future across multiple studies, as we have initiated in this report, may well lead to better prediction of disease manifestation via a systems biology approach.


Asunto(s)
Dengue/genética , Regulación de la Expresión Génica , Adolescente , Niño , Preescolar , Análisis por Conglomerados , Dengue/sangre , Dengue/metabolismo , Virus del Dengue , Femenino , Perfilación de la Expresión Génica/métodos , Humanos , Lactante , Interferones/biosíntesis , Interferones/genética , Masculino , Nicaragua , Reacción en Cadena de la Polimerasa , Transducción de Señal
9.
J Infect Dis ; 201(1): 5-14, 2010 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-19929380

RESUMEN

BACKGROUND: Dengue is the most prevalent mosquito-borne viral disease in humans and a major urban public health problem worldwide. METHODS: A prospective cohort study of approximately 3800 children initially aged 2-9 years was established in Managua, Nicaragua, in 2004 to study the natural history of dengue transmission in an urban pediatric population. Blood samples from healthy subjects were collected annually prior to the dengue season, and identification of dengue cases occurred via enhanced passive surveillance at the study health center. RESULTS: Over the first four years of the study, seroprevalence of anti-dengue virus (DENV) antibodies increased from 22%-40% in the 2-year-old cohort and 90%-95% in the 9-year-old cohort. The incidence of symptomatic dengue cases and the ratio of inapparent to symptomatic DENV infection varied substantially from year to year. The switch in dominant transmission from DENV-1 to DENV-2 was accompanied by an increase in disease severity but, paradoxically, a decrease in transmission. Phylogeographic analysis of full-length DENV-2 sequences revealed strong geographic clustering of dengue cases. CONCLUSIONS: This large-scale cohort study of dengue in the Americas demonstrates year-to-year variation of dengue within a pediatric population, revealing expected patterns in transmission while highlighting the impact of interventions, climate, and viral evolution.


Asunto(s)
Dengue/epidemiología , Dengue/transmisión , Vigilancia de la Población , Distribución por Edad , Niño , Preescolar , Análisis por Conglomerados , Virus del Dengue/clasificación , Femenino , Humanos , Incidencia , Masculino , Nicaragua/epidemiología , Estudios Prospectivos , Estudios Seroepidemiológicos , Serotipificación
10.
Am J Trop Med Hyg ; 81(2): 287-92, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19635885

RESUMEN

Dengue is a major problem worldwide, and improving case management is a significant priority. In consultation with colleagues in Thailand, changes in management of hospitalized dengue cases were introduced in Nicaragua, including oral rather than intravenous (IV) fluids upon admission, continuous monitoring of clinical and laboratory signs, and use of IV fluids principally during the critical phase and colloids in management of shock. Two periods were compared, before (2003) and after (2005) their implementation, to assess impact. In 2003, 182 hospitalized laboratory-confirmed dengue cases 0-14 years of age who presented < or = 5 days post-symptom onset were included in the study; 46 were enrolled in 2005. Outcomes included significant reductions in days of IV fluid administration ( P = 0.0001), number of patients receiving IV fluids ( P < 0.0001), and duration of hospitalization ( P < 0.0001), and a non-significant reduction in the number of admissions to the intensive care unit from 8 in 2003 to 0 in 2005 ( P = 0.36). This study demonstrates concrete gains in dengue patient care and case management.


Asunto(s)
Manejo de Caso , Dengue/terapia , Fluidoterapia/métodos , Hospitales/normas , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Tiempo de Internación , Masculino , Nicaragua , Estudios Retrospectivos
11.
Am J Epidemiol ; 170(1): 120-9, 2009 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-19435864

RESUMEN

Dengue is a mosquito-borne viral disease that is a major public health problem worldwide. In 2004, the Pediatric Dengue Cohort Study was established in Managua, Nicaragua, to study the natural history and transmission of dengue in children. Here, the authors describe the study design, methods, and results from 2004 to 2008. Initially, 3,721 children 2-9 years of age were recruited through door-to-door visits. Each year, new children aged 2 years are enrolled in the study to maintain the age structure. Children are provided with medical care through the study, and data from each medical visit are recorded on systematic study forms. All participants presenting with suspected dengue or undifferentiated fever are tested for dengue by virologic, serologic, and molecular biologic assays. Yearly blood samples are collected to detect inapparent dengue virus infections. Numerous information and communications technologies are used to manage study data, track samples, and maintain quality control, including personal data assistants, barcodes, global information systems, and fingerprint scans. Close collaboration with the Nicaraguan Ministry of Health and use of almost entirely local staff are essential components for success. This study is providing critical data on the epidemiology and transmission of dengue in the Americas needed for future vaccine trials.


Asunto(s)
Dengue/epidemiología , Sistemas de Información Geográfica/organización & administración , Investigación sobre Servicios de Salud/métodos , Gestión de la Información/métodos , Sistemas de Información/estadística & datos numéricos , Evaluación de la Tecnología Biomédica/métodos , Niño , Preescolar , Dengue/transmisión , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Nicaragua/epidemiología , Reproducibilidad de los Resultados , Estudios Retrospectivos , Factores de Tiempo
12.
J Clin Virol ; 43(3): 287-91, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18783984

RESUMEN

BACKGROUND: Numerous immunological approaches exist to diagnose dengue or detect dengue virus (DENV) infections. OBJECTIVES: To determine the best immunological markers and specimen types for dengue diagnosis and for measuring incidence of DENV infection in community-based studies. STUDY DESIGN: In one study, acute- and convalescent-phase samples were collected from hospitalized suspected pediatric dengue cases in Managua, Nicaragua, from September 2003 to February 2004. A second study examined specimens collected in a community setting in Managua before and after the 2003-2004 dengue season to measure incidence of DENV infection. In both studies, detection of anti-DENV IgM, IgA, and IgG in serum, filter-paper blood spots, and saliva was compared to a gold standard performed on serum samples. RESULTS: For dengue diagnosis, the highest sensitivity and specificity was obtained by measuring IgM or IgA in serum or filter-paper blood spots; intermediate and poor results were obtained in saliva for IgM and IgA, respectively. Detection of IgG alone in serum, filter-paper blood spots, or saliva functioned best for measuring DENV infection. CONCLUSIONS: Detection of IgM and IgA in serum and filter-paper blood spots yielded optimal results for diagnosis of dengue cases, whereas IgG was the best marker for measuring incidence of DENV infection.


Asunto(s)
Anticuerpos Antivirales/análisis , Anticuerpos Antivirales/sangre , Sangre/inmunología , Dengue/diagnóstico , Saliva/inmunología , Suero/inmunología , Adolescente , Niño , Preescolar , Dengue/epidemiología , Femenino , Humanos , Inmunoglobulina A/análisis , Inmunoglobulina A/sangre , Inmunoglobulina G/análisis , Inmunoglobulina G/sangre , Inmunoglobulina M/análisis , Inmunoglobulina M/sangre , Lactante , Masculino , Nicaragua/epidemiología , Sensibilidad y Especificidad , Estudios Seroepidemiológicos , Pruebas Serológicas
13.
Virology ; 376(2): 429-35, 2008 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-18452966

RESUMEN

In vitro studies have attempted to identify dengue virus (DEN) target cells in peripheral blood; however, extensive phenotyping of peripheral blood mononuclear cells (PBMCs) from dengue patients has not been reported. PBMCs collected from hospitalized children suspected of acute dengue were analyzed for DEN prM, CD32, CD86, CD14, CD11c, CD16, CD209, CCR7, CD4, and CD8 by flow cytometry to detect DEN antigen in PBMCs and to phenotype DEN-positive cells. DEN prM was detected primarily in activated monocytes (CD14(+), CD32(+), CD86(+), CD11c(+)). A subset of samples analyzed for DEN nonstructural protein 3 (NS3) confirmed that approximately half of DEN antigen-positive cells contained replicating virus. A higher percentage of PBMCs from DHF patients expressed prM, CD86, CD32, and CD11c than did those from DF patients. Increased activation of monocytes and greater numbers of DEN-infected cells were associated with more severe dengue, implicating a role for monocyte activation in dengue immunopathogenesis.


Asunto(s)
Virus del Dengue/patogenicidad , Dengue/inmunología , Dengue/virología , Monocitos/inmunología , Monocitos/virología , Enfermedad Aguda , Antígeno B7-2/análisis , Antígeno B7-2/metabolismo , Recuento de Células , Niño , Citometría de Flujo , Humanos , Recuento de Leucocitos , Leucocitos Mononucleares , Virulencia
14.
J Med Entomol ; 44(5): 851-60, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17915519

RESUMEN

To characterize the production patterns of the dengue virus vector Aedes aegypti (L.) (Diptera: Culcidae), pupal surveys were conducted in selected neighborhoods of two major cities in Nicaragua. In León, 833 houses were visited in July and September 2003, corresponding to the beginning and middle of the dengue season; in Managua, 1,365 homes were visited in July 2003. In total, 7,607 containers were characterized, of which 11% were positive for Ae. aegypti larvae and 4% for pupae. In addition to barrels, potted plants and superficial water on tarps and in puddles were identified as highly productive sites. Univariate and multivariate analysis revealed frequency of container use, use of a lid, and rainwater filling as key variables affecting pupal positivity. Importantly, this survey demonstrated the risk associated with the presence of lids, the limited temporal efficacy of temephos, and the lack of association of water availability with risky water storage practices. Finally, we introduce the concept of an efficiency value and an accompanying graphical display system that can facilitate development of targeted pupal control strategies. These data underscore the importance of entomological surveillance of pupal productivity to gather information from which to derive streamlined, efficient, and effective vector control measures to reduce the density of Aedes mosquito larvae and pupae and thus the risk for dengue.


Asunto(s)
Aedes/fisiología , Insectos Vectores/fisiología , Animales , Cruzamiento , Agua Dulce/parasitología , Insecticidas/farmacología , Larva/efectos de los fármacos , Larva/fisiología , Modelos Logísticos , Control de Mosquitos/métodos , Nicaragua , Densidad de Población , Vigilancia de la Población , Pupa/fisiología , Factores de Riesgo , Temefós/farmacología , Población Urbana
15.
Rev Sci Instrum ; 78(6): 063301, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17614605

RESUMEN

A method for using charge injection devices (CIDs) for detection of high-energy charged particles from inertial-confinement fusion reactions is described. Because of the relatively small depletion region of the CID camera (depletion depth of approximately 7 mum), aluminum foils are placed in front of the device to reduce the energy of the charged particles and maximize the energy deposited in the CID. Simultaneous measurements of (2)H(d,p)(3)H protons with a CID and a surface barrier detector indicate that the CID is an efficient detector of charged fusion products. Tests using high energy alpha particles emitted from a radium-226 source are also reported.


Asunto(s)
Iones Pesados , Radiometría/instrumentación , Procesamiento de Señales Asistido por Computador/instrumentación , Electricidad Estática , Diseño de Equipo , Análisis de Falla de Equipo , Dosis de Radiación , Radiometría/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
Trop Med Int Health ; 11(6): 935-42, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16772016

RESUMEN

To investigate the incidence of dengue virus (DENV) infection in Nicaragua, a 2-year prospective study was conducted in schoolchildren 4-16 years old in the capital city of Managua. Blood samples were collected before the rainy season in 2001, 2002 and 2003, and were assayed for DENV-specific antibodies. Participants were monitored for dengue-like illness, and acute and convalescent blood samples were collected from suspected dengue cases. In 2001 and 2002, 602 and 397 students were recruited, respectively, and paired annual serum samples were available from 467 and 719 participants in 2001-2002 and 2002-2003, respectively. The overall seroprevalence of anti-DENV antibodies was 91%, increasing from 75% at age 4 to 100% at age 16. The incidence of DENV infection was 12% in Year 1 and 6% in Year 2 (P < 0.001). During Year 1, four laboratory-confirmed dengue cases were detected, with one DENV2 isolate; during Year 2, there were six confirmed dengue cases, with one DENV1 isolate. These and additional circulating serotypes were confirmed by plaque reduction neutralisation test. This study demonstrates surprisingly high transmission of DENV in urban Nicaragua.


Asunto(s)
Anticuerpos Antivirales/sangre , Virus del Dengue/inmunología , Dengue/epidemiología , Adolescente , Distribución por Edad , Niño , Preescolar , Dengue/diagnóstico , Dengue/inmunología , Femenino , Humanos , Incidencia , Masculino , Nicaragua/epidemiología , Estudios Prospectivos , Sensibilidad y Especificidad , Estudios Seroepidemiológicos
18.
Am J Trop Med Hyg ; 74(3): 449-56, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16525106

RESUMEN

Dengue, the most prevalent arthropod-borne viral disease of humans, is caused by four serotypes of dengue virus (DENV 1-4). Although all four DENV serotypes cause a range of illness, defining precisely which clinical characteristics are associated with the distinct serotypes has been elusive. A cross-sectional study was conducted on 984 and 313 hospitalized children with confirmed DENV infections during two time periods, respectively, in the same hospitals in Nicaragua: a 3-year period (1999-2001) when DENV-2 accounted for 96% of the viruses identified, and the 2003 dengue season when DENV-1 predominated (87% of identified serotypes). When the two periods were compared, more shock (OR 1.91, 95% CI 1.35-2.71) and internal hemorrhage (OR 2.05, CI 1.16-3.78) were observed in the period when DENV-2 predominated, whereas increased vascular permeability was associated to a greater degree with the DENV-1 period (OR 2.36, CI 1.80-3.09). Compared with the DENV-2 period, the DENV-1 season was associated with more hospitalized primary dengue cases (OR 3.86, CI 2.72-5.48) and more primary DENV infections with severe manifestations (OR 2.93, CI 2.00-4.28). These findings provide new data to characterize the pathogenic potential of distinct DENV serotypes in human populations.


Asunto(s)
Virus del Dengue/crecimiento & desarrollo , Dengue/clasificación , Adolescente , Anticuerpos Antivirales/sangre , Niño , Preescolar , Estudios Transversales , Dengue/sangre , Dengue/patología , Dengue/virología , Femenino , Hematócrito , Hemorragia/patología , Hemorragia/virología , Humanos , Lactante , Masculino , Recuento de Plaquetas , Serotipificación , Choque/patología , Choque/virología , Trombocitopenia/patología , Trombocitopenia/virología
19.
Am J Trop Med Hyg ; 73(6): 1059-62, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16354812

RESUMEN

The World Health Organization (WHO) scheme for classification of dengue severity was evaluated in a three-year study of 1,671 confirmed dengue cases in three Nicaraguan hospitals. The WHO classification of dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) was compared with the presence of hemorrhagic manifestations, signs of vascular permeability, marked thrombocytopenia, and shock in 114 infants, 1,211 children, and 346 adults. We found that strict application of the WHO criteria fails to detect a significant number of patients with severe manifestations of dengue, especially in adults.


Asunto(s)
Dengue/epidemiología , Dengue/patología , Guías como Asunto , Evaluación de Resultado en la Atención de Salud , Índice de Severidad de la Enfermedad , Organización Mundial de la Salud , Adolescente , Adulto , Niño , Preescolar , Dengue/etiología , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Nicaragua/epidemiología , Dengue Grave/epidemiología , Dengue Grave/etiología , Dengue Grave/patología
20.
Am J Trop Med Hyg ; 73(6): 1063-70, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16354813

RESUMEN

To investigate age-related differences in dengue severity, 114 infants, 1,211 children, and 346 adults with laboratory-confirmed dengue virus (DEN) infections presenting to three hospitals in major urban centers in Nicaragua were recruited from 1999 to 2001. The age distribution of dengue cases and the circulating serotype (predominantly DEN2) were representative of national data. Similar results were obtained when either dengue hemorrhagic fever/dengue shock syndrome or its principal manifestations (vascular permeability, internal hemorrhage, marked thrombocytopenia, and/or shock) were analyzed in relation to age and immune status. The burden of disease and of severe dengue was found predominantly in infants 4-9 months of age and in children 5-9 years old, and secondary DEN infection was a risk factor for severity in children. Age-related differences were identified in the prevalence of specific clinical manifestations as well as in their association with a confirmed DEN diagnosis. This represents one of the few comprehensive studies to analyze characteristics of dengue in infants, children, and adults in the same population and highlights age-related differences in dengue severity.


Asunto(s)
Dengue/epidemiología , Adolescente , Adulto , Distribución por Edad , Factores de Edad , Niño , Preescolar , Costo de Enfermedad , Dengue/etiología , Dengue/patología , Femenino , Hospitales Urbanos , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Nicaragua/epidemiología , Prevalencia , Factores de Riesgo , Índice de Severidad de la Enfermedad
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