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1.
Philos Trans A Math Phys Eng Sci ; 380(2215): 20200443, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-34865527

RESUMO

The effect of the 2018 extreme meteorological conditions in Europe on methane (CH4) emissions is examined using estimates from four atmospheric inversions calculated for the period 2005-2018. For most of Europe, we find no anomaly in 2018 compared to the 2005-2018 mean. However, we find a positive anomaly for the Netherlands in April, which coincided with positive temperature and soil moisture anomalies suggesting an increase in biogenic sources. We also find a negative anomaly for the Netherlands for September-October, which coincided with a negative anomaly in soil moisture, suggesting a decrease in soil sources. In addition, we find a positive anomaly for Serbia in spring, summer and autumn, which coincided with increases in temperature and soil moisture, again suggestive of changes in biogenic sources, and the annual emission for 2018 was 33 ± 38% higher than the 2005-2017 mean. These results indicate that CH4 emissions from areas where the natural source is thought to be relatively small can still vary due to meteorological conditions. At the European scale though, the degree of variability over 2005-2018 was small, and there was negligible impact on the annual CH4 emissions in 2018 despite the extreme meteorological conditions. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 2)'.


Assuntos
Metano , Europa (Continente) , Metano/análise , Estações do Ano
2.
Geochem Trans ; 22(1): 4, 2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34379225

RESUMO

The increasing significance of barium (Ba) in environmental and geologic research in recent years has led to interest in the application of the Ba isotopic composition as a tracer for natural materials with complex matrices. Most Ba isotope measurement techniques require separation of Ba from the rest of sample prior to analysis. This paper presents a method using readily available materials and disposable columns that effectively separates Ba from a range of geologic and hydrologic materials, including carbonate minerals, silicate rocks, barite, river water, and fluids with high total dissolved solids and organic content such as oil and gas brines, rapidly and without need for an additional cleanup column. The technique involves off-the-shelf columns and cation exchange resin and a two-reagent elution that uses 2.5 N HCl followed by addition of 2.0 N HNO3. We present data to show that major matrix elements from almost any natural material are separated from Ba in a single column pass, and that the method also effectively reduces or eliminates isobaric interferences from lanthanum and cerium.

3.
Philos Trans R Soc Lond B Biol Sci ; 375(1810): 20190512, 2020 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-32892731

RESUMO

The 2018 drought was one of the worst European droughts of the twenty-first century in terms of its severity, extent and duration. The effects of the drought could be seen in a reduction in harvest yields in parts of Europe, as well as an unprecedented browning of vegetation in summer. Here, we quantify the effect of the drought on net ecosystem exchange (NEE) using five independent regional atmospheric inversion frameworks. Using a network of atmospheric CO2 mole fraction observations, we estimate NEE with at least monthly and 0.5° × 0.5° resolution for 2009-2018. We find that the annual NEE in 2018 was likely more positive (less CO2 uptake) in the temperate region of Europe by 0.09 ± 0.06 Pg C yr-1 (mean ± s.d.) compared to the mean of the last 10 years of -0.08 ± 0.17 Pg C yr-1, making the region close to carbon neutral in 2018. Similarly, we find a positive annual NEE anomaly for the northern region of Europe of 0.02 ± 0.02 Pg C yr-1 compared the 10-year mean of -0.04 ± 0.05 Pg C yr-1. In both regions, this was largely owing to a reduction in the summer CO2 uptake. The positive NEE anomalies coincided spatially and temporally with negative anomalies in soil water. These anomalies were exceptional for the 10-year period of our study. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.


Assuntos
Atmosfera/análise , Ciclo do Carbono , Carbono/análise , Secas , Ecossistema , Europa (Continente)
4.
Cell Transplant ; 28(11): 1404-1419, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31407589

RESUMO

Various cell-based therapies are in development to address chronic and acute skin wound healing, for example for burns and trauma patients. An off-the-shelf source of allogeneic dermal cells could be beneficial for innovative therapies accelerating the healing in extensive wounds where the availability of a patient's own cells is limited. Human fetal-derived dermal fibroblasts (hFDFs) show high in vitro division rates, exhibit low immunological rejection properties, and present scarless wound healing in the fetus, and previous studies on human fetal tissue-derived cell therapies have shown promising results on tissue repair. However, little is known about cell lineage stability and cell differentiation during the cell expansion process, required for any potential therapeutic use. We describe an isolation method, characterize a population, and investigate its potential for cell banking and thus suitability as a potential product for cell grafting therapies. Our results show hFDFs and a bone marrow-derived mesenchymal stem cell (BM-MSC) line shared identification markers and in vitro multilineage differentiation potential into osteogenic, chondrogenic, and adipogenic lineages. The hFDF population exhibited similar cell characteristics as BM-MSCs while producing lower pro-inflammatory cytokine IL-6 levels and higher levels of the wound healing factor hepatocyte growth factor. We demonstrate in vitro differentiation of hFDFs, which may be a problem in maintaining long-term lineage stability, potentially limiting their use for cell banking and therapy development.


Assuntos
Bancos de Espécimes Biológicos , Técnicas de Cultura de Células/métodos , Feto/citologia , Fibroblastos/citologia , Células-Tronco Mesenquimais/citologia , Pele/citologia , Cicatrização , Adipogenia/genética , Linhagem da Célula/genética , Movimento Celular/genética , Proliferação de Células/genética , Condrogênese/genética , Citocinas/metabolismo , Feto/metabolismo , Fibroblastos/metabolismo , Fibroblastos/transplante , Humanos , Células-Tronco Mesenquimais/metabolismo , Osteogênese/genética , Pele/metabolismo , Transplantes , Cicatrização/efeitos dos fármacos , Cicatrização/genética , Cicatrização/fisiologia
5.
Aust Vet J ; 95(3): 85-88, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28239856

RESUMO

BACKGROUND: This study was performed to investigate the efficacy of a morantel-abamectin combination for the treatment of macrocyclic lactone (ML)-resistant Parascaris spp. infections in foals. METHODS: Foals on five properties with a Parascaris faecal egg count (FEC) > 50 eggs per gram were used to estimate the FEC reduction (FECR) and efficacy of the anthelmintic combination. RESULTS & CONCLUSION: On all properties, resistance to ivermectin and abamectin was present and the Parascaris FECR in foals administered the morantel-abamectin combination was > 99%, indicating that this combination effectively controlled ML-resistant parasites.


Assuntos
Antinematódeos/uso terapêutico , Infecções por Ascaridida/veterinária , Ascaridoidea/efeitos dos fármacos , Doenças dos Cavalos/tratamento farmacológico , Ivermectina/análogos & derivados , Morantel/uso terapêutico , Animais , Antinematódeos/administração & dosagem , Infecções por Ascaridida/tratamento farmacológico , Infecções por Ascaridida/parasitologia , Combinação de Medicamentos , Resistência a Medicamentos , Doenças dos Cavalos/parasitologia , Cavalos/parasitologia , Ivermectina/administração & dosagem , Ivermectina/uso terapêutico , Morantel/administração & dosagem , Resultado do Tratamento
6.
Nat Commun ; 7: 10724, 2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-26911442

RESUMO

Increasing atmospheric carbon dioxide (CO2) is the principal driver of anthropogenic climate change. Asia is an important region for the global carbon budget, with 4 of the world's 10 largest national emitters of CO2. Using an ensemble of seven atmospheric inverse systems, we estimated land biosphere fluxes (natural, land-use change and fires) based on atmospheric observations of CO2 concentration. The Asian land biosphere was a net sink of -0.46 (-0.70-0.24) PgC per year (median and range) for 1996-2012 and was mostly located in East Asia, while in South and Southeast Asia the land biosphere was close to carbon neutral. In East Asia, the annual CO2 sink increased between 1996-2001 and 2008-2012 by 0.56 (0.30-0.81) PgC, accounting for ∼35% of the increase in the global land biosphere sink. Uncertainty in the fossil fuel emissions contributes significantly (32%) to the uncertainty in land biosphere sink change.

7.
ACS Macro Lett ; 5(4): 430-434, 2016 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-35607237

RESUMO

We study the conformations of polymer chains in polymer-graphene oxide nanocomposites. We show that the chains have a reduced radius of gyration that is consistent with confinement at a solid interface in the melt, as is expected for well-dispersed, high aspect ratio nanoparticles that are much larger than the polymer coil size. We show that confinement of the polymer chains causes a corresponding reduction in interchain entanglements, and we calculate a contribution to the plateau modulus from the distorted polymer network via a simple scaling argument. Our results are a significant step forward in understanding how two-dimensional nanoparticles affect global material properties at low loadings.

8.
J Fish Dis ; 39(2): 117-28, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25630226

RESUMO

A Jaundice Syndrome occurs sporadically among sea-pen-farmed Chinook Salmon in British Columbia, the westernmost province of Canada. Affected salmon are easily identified by a distinctive yellow discolouration of the abdominal and periorbital regions. Through traditional diagnostics, no bacterial or viral agents were cultured from tissues of jaundiced Chinook Salmon; however, piscine reovirus (PRV) was identified via RT-rPCR in all 10 affected fish sampled. By histopathology, Jaundice Syndrome is an acute to peracute systemic disease, and the time from first clinical signs to death is likely <48 h; renal tubular epithelial cell necrosis is the most consistent lesion. In an infectivity trial, Chinook Salmon, Sockeye Salmon and Atlantic Salmon, intraperitoneally inoculated with a PRV-positive organ homogenate from jaundiced Chinook Salmon, developed no gross or microscopic evidence of jaundice despite persistence of PRV for the 5-month holding period. The results from this study demonstrate that the Jaundice Syndrome was not transmissible by injection of material from infected fish and that PRV was not the sole aetiological factor for the condition. Additionally, these findings showed the Pacific coast strain of PRV, while transmissible, was of low pathogenicity for Atlantic Salmon, Chinook Salmon and Sockeye Salmon.


Assuntos
Doenças dos Peixes/transmissão , Infecções por Reoviridae/veterinária , Reoviridae/fisiologia , Salmonidae/virologia , Doença Aguda , Animais , Colúmbia Britânica , Doenças dos Peixes/mortalidade , Doenças dos Peixes/patologia , Doenças dos Peixes/virologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Fígado/fisiopatologia , Proteínas de Resistência a Myxovirus/genética , Reoviridae/patogenicidade , Infecções por Reoviridae/transmissão , Salmonidae/genética , Síndrome
9.
Chem Commun (Camb) ; 51(23): 4838-41, 2015 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-25695462

RESUMO

Understanding and probing small molecule uptake in cells is challenging, requiring sterically large chemical labels, or radioactive isotopes. Here, the uptake of deuterated sugars by Mycobacterium smegmatis, a non-pathogenic model of Mycobacterium tuberculosis, has been investigated using ion-beam (nuclear reaction) analysis demonstrating a new technique for label-free nutrient acquisition measurement.


Assuntos
Metabolismo dos Carboidratos , Carboidratos/química , Deutério/química , Mycobacterium smegmatis/metabolismo , Transporte Biológico/fisiologia
10.
ACS Appl Mater Interfaces ; 4(12): 6747-51, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23193941

RESUMO

Non-equilibrium plasmachemical deposition using platinum(II) hexafluoroacetylacetonate precursor leads to the single-step formation of nanocomposite layers comprising an organic host matrix embedded with metal particles of size less than 5 nm. These multifunctional nanocomposite films are found to display both ionic and electronic conductivities.

11.
Eur Phys J E Soft Matter ; 33(4): 283-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21086015

RESUMO

Thin films of polymer mixtures made by spin-coating can phase separate in two ways: by forming lateral domains, or by separating into distinct layers. The latter situation (self-stratification or vertical phase separation) could be advantageous in a number of practical applications, such as polymer optoelectronics. We demonstrate that, by controlling the evaporation rate during the spin-coating process, we can obtain either self-stratification or lateral phase separation in the same system, and we relate this to a previously hypothesised mechanism for phase separation during spin-coating in thin films, according to which a transient wetting layer breaks up due to a Marangoni-type instability driven by a concentration gradient of solvent within the drying film. Our results show that rapid evaporation leads to a laterally phase-separated structure, while reducing the evaporation rate suppresses the interfacial instability and leads to a self-stratified final film.


Assuntos
Materiais Revestidos Biocompatíveis/análise , Polímeros/análise , Solventes/química , Materiais Revestidos Biocompatíveis/química , Eletrônica , Transição de Fase , Polímeros/química , Propriedades de Superfície , Termodinâmica , Tolueno/química , Pressão de Vapor , Volatilização
12.
Allergy ; 65(5): 606-15, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19845575

RESUMO

BACKGROUND: Epidemiological studies of diet and asthma have focused on relations with intakes of individual nutrients and foods and evidence has been conflicting. Few studies have examined associations with dietary patterns. METHODS: We carried out a population-based case-control study of asthma in adults aged between 16 and 50 in South London, UK. Information about usual diet was obtained by food frequency questionnaire and we used principal components analysis to define five dietary patterns in controls. We used logistic and linear regression, controlling for confounders, to relate these patterns to asthma, asthma severity, rhinitis and chronic bronchitis in 599 cases and 854 controls. RESULTS: Overall, there was weak evidence that a 'vegetarian' dietary pattern was positively associated with asthma [adjusted odds ratio comparing top vs bottom quintile of pattern score 1.43 (95% CI: 0.93-2.20), P trend 0.075], and a 'traditional' pattern (meat and vegetables) was negatively associated [OR 0.68 (0.45-1.03), P trend 0.071]. These associations were stronger amongst nonsupplement users (P trend 0.030 and 0.001, respectively), and the association with the 'vegetarian' pattern was stronger amongst whites (P trend 0.008). No associations were observed with asthma severity. A 'prudent' dietary pattern (wholemeal bread, fish and vegetables) was positively associated with chronic bronchitis [OR 2.61 (1.13-6.05), P trend 0.025], especially amongst nonsupplement users (P trend 0.002). CONCLUSIONS: Overall there were no clear relations between dietary patterns and adult asthma; associations in nonsupplement users and whites require confirmation. The finding for chronic bronchitis was unexpected and also requires replication.


Assuntos
Asma/epidemiologia , Asma/etiologia , Dieta/efeitos adversos , Adolescente , Adulto , Bronquite Crônica/epidemiologia , Bronquite Crônica/etiologia , Estudos de Casos e Controles , Suplementos Nutricionais/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Componente Principal , Inquéritos e Questionários , Reino Unido/epidemiologia , Adulto Jovem
13.
Health Phys ; 97(2 Suppl): S140-4, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19590267

RESUMO

Ongoing uncertainties have existed regarding possible effects at low photon energies of two copper filters covering Element 1 of the Harshaw Type-8814 thermoluminescent dosimeter badge casing. To address these, Brookhaven National Laboratory's (BNL) Personnel Monitoring Group conducted a test in which Type-8814 badges with one copper filter covering Element 1 were irradiated at several low-energy levels side-by-side with the same number of badges with two copper filters covering Element 1. A review of exposures to personnel at Brookhaven Laboratory to possible low-energy photon flux was also conducted. From both the test and the review of exposures, it can be concluded that, for radiological work under the conditions at BNL, there is no apparent dosimetric difference if one or two copper filters cover Element 1 of the Type-8814 badge.


Assuntos
Cobre , Filtração , Exposição Ocupacional , Doses de Radiação , Dosimetria Termoluminescente/efeitos adversos , Humanos
14.
J Food Sci ; 73(5): M239-44, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18577007

RESUMO

This study investigated the use of sodium levulinate to prevent outgrowth of Listeria monocytogenes in refrigerated ready-to-eat (RTE) meat products. Turkey breast roll and bologna were formulated to contain 1%, 2%, or 3% (w/w) sodium levulinate, 2% sodium lactate, a 2% combination of sodium lactate and sodium diacetate (1.875% sodium lactate and 0.125% sodium diacetate), or no antimicrobial (control). Samples of the RTE products were sliced, inoculated with 10(2) to 10(3) CFU/cm(2) of a 5-strain cocktail of L. monocytogenes, vacuum packaged, and stored at refrigeration temperature for 0 to 12 wk. Counts reached 10(8) CFU/cm(2) on control turkey roll product after 8 wk, and over 10(7) CFU/cm(2) on control bologna after 12 wk. Addition of 2% or more sodium levulinate to turkey roll and 1% or more sodium levulinate to bologna completely prevented growth of L. monocytogenes during 12 wk of refrigerated storage. A consumer taste panel with pathogen-free samples found no differences in the overall liking among the preparations of turkey roll or among preparations of bologna. These results show that sodium levulinate is at least as effective at inhibiting outgrowth of L. monocytogenes in RTE meat products as the current industry standards of lactate or lactate and diacetate, and levulinate addition does not alter the overall liking of the RTE meat products.


Assuntos
Antibacterianos/farmacologia , Conservação de Alimentos/métodos , Listeria monocytogenes/efeitos dos fármacos , Produtos da Carne/microbiologia , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Embalagem de Alimentos/métodos , Ácidos Levulínicos/farmacologia , Listeria monocytogenes/crescimento & desenvolvimento , Acetato de Sódio/farmacologia , Lactato de Sódio/farmacologia , Temperatura , Fatores de Tempo
15.
Allergy ; 63(4): 425-31, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18315730

RESUMO

BACKGROUND: There are large differences in the prevalence of atopic disease between urban and rural areas of developing countries, without good explanation. Diet has been associated with atopic disease, but studies of specific nutrients are contradictory, cross-sectional studies often being unsupported by trials. We investigated diet as an explanation for the difference in the prevalence of atopy between urban and rural areas in South Africa. METHODS: A cross-sectional analysis of food frequency questionnaires and allergen skin tests from 698 children aged 8-13 years, recruited from 24 schools in Cape Province, South Africa, who were taking part in a case-control study of exercise-induced bronchospasm. Food frequency data were analysed with a principal components analysis (PCA). RESULTS: The first two principal components of diet explained 25% of the variance, and discriminated almost perfectly between urban and rural subjects. The 'urban' component of diet was strongly associated with positive skin tests even after adjusting for urban residence. There were no significant associations between individual foods or nutrients and positive skin tests, allowing for multiple testing. CONCLUSIONS: Diet explains part of the difference in prevalence between urban and rural areas. The ability to demonstrate this using PCA, but not by exhaustive analysis of all foods, reflects the value of reducing the number of dietary dimensions. The number of foods and nutrients which can be assessed, and the possibility of confounding and effect modification, make it difficult to identify the features of diet most directly implicated in disease. This may explain inconsistencies in dietary studies.


Assuntos
Dieta , Hipersensibilidade Imediata/epidemiologia , Saúde da População Rural , Saúde da População Urbana , Adolescente , Criança , Feminino , Humanos , Hipersensibilidade Imediata/etiologia , Masculino , Prevalência , Análise de Componente Principal , Testes Cutâneos , África do Sul/epidemiologia , Inquéritos e Questionários
16.
J Virol ; 80(22): 10919-30, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16943285

RESUMO

The stress-induced host cell factors initiating the expression of the herpes simplex virus lytic cycle from the latent viral genome are not known. Previous studies have focused on the effect of specific viral proteins on reactivation, i.e., the production of detectable infectious virus. However, identification of the viral protein(s) through which host cell factors transduce entry into the lytic cycle and analysis of the promoter(s) of this (these) first protein(s) will provide clues to the identity of the stress-induced host cell factors important for reactivation. In this report, we present the first strategy developed for this type of analysis and use this strategy to test the established hypothesis that the herpes simplex virus ICP0 protein initiates reactivation from the latent state. To this end, ICP0 null and promoter mutants were analyzed for the abilities (i) to exit latency and produce lytic-phase viral proteins (initiate reactivation) and (ii) to produce infectious viral progeny (reactivate) in explant and in vivo. Infection conditions were manipulated so that approximately equal numbers of latent infections were established by the parental strains, the mutants, and their genomically restored counterparts, eliminating disparate latent pool sizes as a complicating factor. Following hyperthermic stress (HS), which induces reactivation in vivo, equivalent numbers of neurons exited latency (as evidenced by the expression of lytic-phase viral proteins) in ganglia latently infected with either the ICP0 null mutant dl1403 or the parental strain. In contrast, infectious virus was detected in the ganglia of mice latently infected with the parental strain but not with ICP0 null mutant dl1403 or FXE. These data demonstrate that the role of ICP0 in the process of reactivation is not as a component of the switch from latency to lytic-phase gene expression; rather, ICP0 is required after entry into the lytic cycle has occurred. Similar analyses were carried out with the DeltaTfi mutant, which contains a 350-bp deletion in the ICP0 promoter, and the genomically restored isolate, DeltaTfiR. The numbers of latently infected neurons exiting latency were not different for DeltaTfi and DeltaTfiR. However, DeltaTfi did not reactivate in vivo, whereas DeltaTfiR reactivated in approximately 38% of the mice. In addition, ICP0 was detected in DeltaTfiR-infected neurons exiting latency but was not detected in those neurons exiting latency infected with DeltaTfi. We conclude that while ICP0 is important and perhaps essential for infectious virus production during reactivation in vivo, this protein is not required and appears to play no major role in the initiation of reactivation in vivo.


Assuntos
Herpesvirus Humano 1/fisiologia , Proteínas Imediatamente Precoces/fisiologia , Ubiquitina-Proteína Ligases/fisiologia , Ativação Viral/fisiologia , Animais , DNA Viral/análise , Modelos Animais de Doenças , Genoma Viral , Herpes Simples/virologia , Proteínas Imediatamente Precoces/genética , Masculino , Camundongos , Mutação , Neurônios/virologia , Regiões Promotoras Genéticas , RNA Mensageiro/biossíntese , RNA Viral/biossíntese , Deleção de Sequência , Transcrição Gênica , Ubiquitina-Proteína Ligases/genética , Latência Viral , Replicação Viral/genética
17.
Ir J Med Sci ; 175(4): 79-80, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17312837

RESUMO

BACKGROUND: Small bowel volvulus is rare in adults and often has a precipitating factor. METHODS: This report describes a case of small bowel volvulus secondary to a mesenteric lipoma and reviews the literature describing this condition. CONCLUSION: Mesenteric lipoma is a rare precipitating cause of small bowel volvulus in adults. Computed tomography scanning may be useful for diagnosis preoperatively. The treatment of choice is surgery with complete excision of the lipoma.


Assuntos
Doenças do Íleo/etiologia , Volvo Intestinal/etiologia , Lipoma/complicações , Neoplasias Peritoneais/complicações , Adulto , Humanos , Doenças do Íleo/cirurgia , Volvo Intestinal/cirurgia , Lipoma/cirurgia , Masculino , Mesentério , Neoplasias Peritoneais/cirurgia , Tomografia Computadorizada por Raios X
18.
J Virol ; 80(1): 38-50, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16352529

RESUMO

The herpes simplex virus genome can enter a repressed transcriptional state (latency) in sensory neurons of the host nervous system. Although reduced permissiveness of the neuronal environment is widely accepted as a causal factor, the molecular pathway(s) directing and maintaining the viral genome in the latent state remains undefined. Over the past decade, the field has been strongly influenced by the observations of Kosz-Vnenchak et al., which have been interpreted to indicate that, in sensory neurons in vivo, a critical level of viral DNA synthesis within the neuron is required for sufficient viral immediate-early (IE) and early (E) gene expression (M. Kosz-Vnenchak, J. Jacobson, D. M. Coen, and D. M. Knipe, J. Virol. 67:5383-5393, 1993). The levels of IE and E genes are, in turn, thought to regulate the decision to enter the lytic cycle or latency. We have reexamined this issue using new strategies for in situ detection and quantification of viral gene expression in whole tissues. Our results using thymidine kinase-null and rescued mutants as well as wild-type strains in conjunction with viral DNA synthesis blockers demonstrate that (i) despite inhibition of viral DNA replication, many neurons express lytic viral proteins, including IE proteins, during acute infection in the ganglion; (ii) at early times postinoculation, the number of neurons expressing viral proteins in the ganglion is not reduced by inhibition of viral DNA replication; and (iii) following a reactivation stimulus, the numbers of neurons and apparent levels of lytic viral proteins, including IE proteins, are not reduced by inhibition of viral DNA replication. We conclude that viral DNA replication in the neuron per se does not regulate IE gene expression or entry into the lytic cycle.


Assuntos
DNA Viral/fisiologia , Neurônios/metabolismo , Simplexvirus/fisiologia , Gânglio Trigeminal/metabolismo , Latência Viral/fisiologia , Animais , Fatores de Transcrição de Zíper de Leucina Básica , DNA Viral/biossíntese , Regulação Viral da Expressão Gênica , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/metabolismo , Neurônios/virologia , Sistema Nervoso Periférico , Proteínas Repressoras , Simplexvirus/genética , Simplexvirus/metabolismo , Gânglio Trigeminal/patologia , Gânglio Trigeminal/virologia , Proteínas Virais , Replicação Viral
19.
Eur Respir J ; 26(3): 449-52, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16135726

RESUMO

Epidemiological studies have suggested that a high consumption of apples may protect against asthma and chronic obstructive pulmonary disease. This effect has been attributed to their high flavonoid content, but few studies have investigated the relationship between flavonoid intake and obstructive lung disease directly. In a population-based, case-control study of 1,471 adults aged 16-50 yrs in London (UK), the present study examined whether dietary intake of catechins, flavonols and flavones was negatively associated with asthma, asthma severity and chronic sputum production. Asthma was defined by positive responses to a standard screening questionnaire in 1996 and information about usual diet was obtained by a food frequency questionnaire in 1997. After controlling for potential confounders, dietary intake of these three flavonoid subclasses was not significantly associated with asthma, (odds ratio per quintile (95% confidence interval) = 0.94 (0.86-1.02); 1.00 (0.92-1.09); 0.98 (0.88 -1.08) for flavones, flavonols and total catechins, respectively) nor was it associated with asthma severity, or chronic sputum production. In conclusion, no evidence was found for a protective effect of three major subclasses of dietary flavonoids on asthma. It is possible that other flavonoids or polyphenols present in apples may explain the protective effect of apples on obstructive lung disease.


Assuntos
Asma/epidemiologia , Dieta , Flavonoides , Escarro , Adolescente , Adulto , Asma/prevenção & controle , Estudos de Casos e Controles , Doença Crônica , Inquéritos sobre Dietas , Humanos , Malus , Pessoa de Meia-Idade , Razão de Chances , Índice de Gravidade de Doença
20.
Cochrane Database Syst Rev ; (4): CD003177, 2004 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-15495044

RESUMO

BACKGROUND: It has been suggested that omega 3 (W3, n-3 or omega-3) fats from oily fish and plants are beneficial to health. OBJECTIVES: To assess whether dietary or supplemental omega 3 fatty acids alter total mortality, cardiovascular events or cancers using both RCT and cohort studies. SEARCH STRATEGY: Five databases including CENTRAL, MEDLINE and EMBASE were searched to February 2002. No language restrictions were applied. Bibliographies were checked and authors contacted. SELECTION CRITERIA: RCTs were included where omega 3 intake or advice was randomly allocated and unconfounded, and study duration was at least six months. Cohorts were included where a cohort was followed up for at least six months and omega 3 intake estimated. DATA COLLECTION AND ANALYSIS: Studies were assessed for inclusion, data extracted and quality assessed independently in duplicate. Random effects meta-analysis was performed separately for RCT and cohort data. MAIN RESULTS: Forty eight randomised controlled trials (36,913 participants) and 41 cohort analyses were included. Pooled trial results did not show a reduction in the risk of total mortality or combined cardiovascular events in those taking additional omega 3 fats (with significant statistical heterogeneity). Sensitivity analysis, retaining only studies at low risk of bias, reduced heterogeneity and again suggested no significant effect of omega 3 fats. Restricting analysis to trials increasing fish-based omega 3 fats, or those increasing short chain omega 3s, did not suggest significant effects on mortality or cardiovascular events in either group. Subgroup analysis by dietary advice or supplementation, baseline risk of CVD or omega 3 dose suggested no clear effects of these factors on primary outcomes. Neither RCTs nor cohorts suggested increased relative risk of cancers with higher omega 3 intake but estimates were imprecise so a clinically important effect could not be excluded. REVIEWERS' CONCLUSIONS: It is not clear that dietary or supplemental omega 3 fats alter total mortality, combined cardiovascular events or cancers in people with, or at high risk of, cardiovascular disease or in the general population. There is no evidence we should advise people to stop taking rich sources of omega 3 fats, but further high quality trials are needed to confirm suggestions of a protective effect of omega 3 fats on cardiovascular health. There is no clear evidence that omega 3 fats differ in effectiveness according to fish or plant sources, dietary or supplemental sources, dose or presence of placebo.


Assuntos
Doenças Cardiovasculares/dietoterapia , Suplementos Nutricionais , Ácidos Graxos Ômega-3/uso terapêutico , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/prevenção & controle , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
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