Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124
Filtrar
1.
Nat Methods ; 18(8): 953-958, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34312564

RESUMO

Unbiased quantitative analysis of macroscopic biological samples demands fast imaging systems capable of maintaining high resolution across large volumes. Here we introduce RAPID (rapid autofocusing via pupil-split image phase detection), a real-time autofocus method applicable in every widefield-based microscope. RAPID-enabled light-sheet microscopy reliably reconstructs intact, cleared mouse brains with subcellular resolution, and allowed us to characterize the three-dimensional (3D) spatial clustering of somatostatin-positive neurons in the whole encephalon, including densely labeled areas. Furthermore, it enabled 3D morphological analysis of microglia across the entire brain. Beyond light-sheet microscopy, we demonstrate that RAPID maintains high image quality in various settings, from in vivo fluorescence imaging to 3D tracking of fast-moving organisms. RAPID thus provides a flexible autofocus solution that is suitable for traditional automated microscopy tasks as well as for quantitative analysis of large biological specimens.


Assuntos
Encéfalo/anatomia & histologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Microglia/citologia , Microscopia de Fluorescência/métodos , Animais , Masculino , Camundongos
2.
Pharmacol Res ; 183: 106401, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35987482

RESUMO

We previously demonstrated that prenatal exposure to valproic acid (VPA), an environmental model of autism spectrum disorder (ASD), leads to a hyperexcitable phenotype associated with downregulation of inward-rectifying potassium currents in nucleus accumbens (NAc) medium spiny neurons (MSNs) of adolescent rats. Aberrant mTOR pathway function has been associated with autistic-like phenotypes in multiple animal models, including gestational exposure to VPA. The purpose of this work was to probe the involvement of the mTOR pathway in VPA-induced alterations of striatal excitability. Adolescent male Wistar rats prenatally exposed to VPA were treated acutely with the mTOR inhibitor rapamycin and used for behavioral tests, ex vivo brain slice electrophysiology, single-neuron morphometric analysis, synaptic protein quantification and gene expression analysis in the NAc. We report that postnatal rapamycin ameliorates the social deficit and reverts the abnormal excitability, but not the inward-rectifying potassium current defect, of accumbal MSNs. Synaptic transmission and neuronal morphology were largely unaffected by prenatal VPA exposure or postnatal rapamycin treatment. Transcriptome analysis revealed extensive deregulation of genes implied in neurodevelopmental disorders and ionic mechanisms exerted by prenatal VPA, which was partially reverted by postnatal rapamycin. The results of this work support the existence of antagonistic interaction between mTOR and VPA-induced pathways on social behavior, neurophysiological phenotype and gene expression profile, thus prompting further investigation of the mTOR pathway in the quest for specific therapeutic targets in ASD.


Assuntos
Transtorno do Espectro Autista , Efeitos Tardios da Exposição Pré-Natal , Animais , Transtorno do Espectro Autista/induzido quimicamente , Transtorno do Espectro Autista/tratamento farmacológico , Transtorno do Espectro Autista/metabolismo , Comportamento Animal , Modelos Animais de Doenças , Feminino , Masculino , Neurônios/metabolismo , Fenótipo , Potássio , Gravidez , Ratos , Ratos Wistar , Sirolimo/farmacologia , Sirolimo/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Ácido Valproico/farmacologia
3.
Int J Biometeorol ; 66(1): 71-86, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34846567

RESUMO

Even if the sensitivity of vegetation phenology to climate change has been accepted on global and continental scales, the correlation between global warming and phenotypic variability shows a modulated answer depending on altitude, latitude, and the local seasonal thermal trend. To connect global patterns of change with local effects, we investigated the impact of the observed signal of warming found in Central Italy on two different willow species, Salix acutifolia and Salix smithiana, growing in three phenological gardens of the International Phenological Gardens' network (IPG) located in different orographic positions. The time series of temperatures and phenological data for the period 2005-2018 were analysed first to find trends over time in the three gardens and then to correlate the recent local warming and the change in the two species phenology. The results confirmed the correlation between phenological trends and local trend of temperatures. In particular: budburst showed a trend of advancement of 1.4 days/year on average in all three gardens; flowering showed a divergent pattern between the gardens of either advancement of 1.0 days/year on average or delay of 1.1 days/year on average; while senescence showed a delay reaching even 3.3 days/year, although significant in only two gardens for both species. These trends were found to be correlated mainly with the temperatures of the months preceding the occurrence of the phase, with a shift in terms of days of the year (DOY) of the two species. Our conclusion is that the observed warming in Central Italy played a key role in controlling the phenophases occurrences of the two willow species, and that the orographic forcing leads to the different shift in DOY of phenophases (from 5 to 20 days) due to the local thermal forcing of the three phenological gardens.


Assuntos
Altitude , Mudança Climática , Aquecimento Global , Estações do Ano , Temperatura
4.
Proc Natl Acad Sci U S A ; 114(22): 5737-5742, 2017 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-28507142

RESUMO

Well-coordinated activation of all cardiomyocytes must occur on every heartbeat. At the cell level, a complex network of sarcolemmal invaginations, called the transverse-axial tubular system (TATS), propagates membrane potential changes to the cell core, ensuring synchronous and uniform excitation-contraction coupling. Although myocardial conduction of excitation has been widely described, the electrical properties of the TATS remain mostly unknown. Here, we exploit the formal analogy between diffusion and electrical conductivity to link the latter with the diffusional properties of TATS. Fluorescence recovery after photobleaching (FRAP) microscopy is used to probe the diffusion properties of TATS in isolated rat cardiomyocytes: A fluorescent dextran inside TATS lumen is photobleached, and signal recovery by diffusion of unbleached dextran from the extracellular space is monitored. We designed a mathematical model to correlate the time constant of fluorescence recovery with the apparent diffusion coefficient of the fluorescent molecules. Then, apparent diffusion is linked to electrical conductivity and used to evaluate the efficiency of the passive spread of membrane depolarization along TATS. The method is first validated in cells where most TATS elements are acutely detached by osmotic shock and then applied to probe TATS electrical conductivity in failing heart cells. We find that acute and pathological tubular remodeling significantly affect TATS electrical conductivity. This may explain the occurrence of defects in action potential propagation at the level of single T-tubules, recently observed in diseased cardiomyocytes.


Assuntos
Potenciais de Ação/fisiologia , Extensões da Superfície Celular/fisiologia , Sistema de Condução Cardíaco/fisiologia , Miócitos Cardíacos/fisiologia , Animais , Sinalização do Cálcio/fisiologia , Células Cultivadas , Acoplamento Excitação-Contração/fisiologia , Recuperação de Fluorescência Após Fotodegradação , Masculino , Modelos Teóricos , Miocárdio/metabolismo , Ratos , Ratos Endogâmicos WKY , Sarcolema/fisiologia , Retículo Sarcoplasmático/metabolismo
6.
Nutr Metab Cardiovasc Dis ; 25(8): 734-41, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26026214

RESUMO

BACKGROUND AND AIMS: Very little information is available on whether docosahexaenoic acid (DHA) supplementation has a beneficial effect on liver fat and cardiovascular disease (CVD) risk factors in children with nonalcoholic fatty liver disease (NAFLD). In a double-blind, placebo-controlled randomized trial we investigated whether 6-month treatment with DHA improves hepatic fat and other fat depots, and their associated CVD risk factors in children with biopsy-proven NAFLD. METHODS AND RESULTS: Of 58 randomized children, 51 (25 DHA, 26 placebo) completed the study. The main outcome was the change in hepatic fat fraction as estimated by magnetic resonance imaging. Secondary outcomes were changes in visceral adipose tissue (VAT), epicardial adipose tissue (EAT), and left ventricular (LV) function, as well as alanine aminotransferase (ALT), triglycerides, body mass index-standard deviation score (BMI-SDS), and insulin sensitivity. At 6 months, the liver fat was reduced by 53.4% (95% CI, 33.4-73.4) in the DHA group, as compared with 22.6% (6.2-39.0) in the placebo group (P = 0.040 for the comparison between the two groups). Likewise, in the DHA group VAT and EAT were reduced by 7.8% (0-18.3) and 14.2% (0-28.2%), as compared with 2.2% (0-8.1) and 1.7% (0-6.8%) in the placebo group, respectively (P = 0.01 for both comparisons). There were no significant between-group changes for LV function as well as BMI-SDS and ALT, while fasting insulin and triglycerides significantly decreased in the DHA-treated children (P = 0.028 and P = 0.041, respectively). CONCLUSIONS: DHA supplementation decreases liver and visceral fat, and ameliorates metabolic abnormalities in children with NAFLD.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Fígado/efeitos dos fármacos , Imageamento por Ressonância Magnética , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Sobrepeso/dietoterapia , Adolescente , Alanina Transaminase/sangue , Biópsia , Índice de Massa Corporal , Criança , Ácidos Docosa-Hexaenoicos/administração & dosagem , Método Duplo-Cego , Jejum/sangue , Ácidos Graxos Insaturados/farmacologia , Feminino , Humanos , Insulina/sangue , Gordura Intra-Abdominal/efeitos dos fármacos , Gordura Intra-Abdominal/patologia , Fígado/patologia , Masculino , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/patologia , Sobrepeso/sangue , Sobrepeso/patologia , Pericárdio/efeitos dos fármacos , Pericárdio/patologia , Fatores de Risco , Resultado do Tratamento , Triglicerídeos/sangue , Função Ventricular Esquerda/efeitos dos fármacos
7.
Int J Clin Pract ; 68(8): 995-1000, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24852701

RESUMO

BACKGROUND: A high incidence of erectile dysfunction (ED) among patients with obstructive sleep apnoea syndrome (OSAS) has been reported, with a strong correlation between obstructive sleep apnoea, ED, and quality of life (QOL), and it has been estimated that 10-60% of patients with OSAS suffer from ED. In this prospective randomised controlled trial, we investigated 82 men with ED consecutively who were referred to the outpatient clinic for sleep disorders and had severe OSAS (AHI> 30 events/h) without any other comorbidities as a possible cause of ED. The aim of this study was to evaluate and compare the efficacy of sildenafil vs. continuous positive airway pressure (CPAP) in men with ED and severe OSAS. METHODS: Eighty-two patients were randomised to two main treatment groups: group 1 patients (n = 41) were treated with 100-mg sildenafil 1 h before sexual intercourse without CPAP, and group 2 patients (n = 41 men) were treated with only nasal CPAP during night time sleep. Both groups were evaluated with the same questionnaires (International Index of Erectile Function-EF domain; Sex Encounter Profile; Erectile Dysfunction Inventory Treatment Satisfaction) 12 weeks after treatment. RESULTS: In patients receiving sildenafil treatment, 58.2% of those who attempted sexual intercourses were successful compared to 30.4% in the CPAP group. The mean number of successful attempts per week was significantly higher in the sildenafil group compared with the CPAP group (2.9 vs. 1.7, respectively; p < 0.0001). The mean IIEF-EF domain scores were significantly higher in the sildenafil group compared with the CPAP group (p < 0.0001). The overall satisfaction rate was 68% with sildenafil treatment and 29% with CPAP treatment. CONCLUSIONS: This study confirms that severe OSAS is strongly associated with erectile dysfunction. CPAP and sildenafil (100 mg) are safe and effective therapies for OSAS-related ED patients. In the present study sildenafil was more effective than CPAP in treating ED associated with OSAS, as indicated by a significantly higher rate of successful attempts at intercourse and higher IIEF-EF domain scores. Our study, to date, is the only that has investigated sildenafil in patients with severe OSAS.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas/estatística & dados numéricos , Disfunção Erétil/tratamento farmacológico , Piperazinas/uso terapêutico , Citrato de Sildenafila/uso terapêutico , Síndromes da Apneia do Sono/tratamento farmacológico , Vasodilatadores/uso terapêutico , Adulto , Coito/fisiologia , Terapia Combinada , Pressão Positiva Contínua nas Vias Aéreas/normas , Disfunção Erétil/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Piperazinas/efeitos adversos , Estudos Prospectivos , Qualidade de Vida , Citrato de Sildenafila/administração & dosagem , Síndromes da Apneia do Sono/terapia , Inquéritos e Questionários , Vasodilatadores/administração & dosagem
8.
Minerva Urol Nefrol ; 66(4): 225-32, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25034330

RESUMO

AIM: The aim of the study was to compare Cistiquer, a new phytotherapeutic product developed for chronic bladder inflammatory diseases, and intra-vesical administration of gentamicin plus betametasone, in females with urethral syndrome. METHODS: Between september 2013 and may 2014, 60 women with urethral syndrome and trigonitis were incuded in this study. Patients were randomly assigned to treatment with intra-vesical administration of betametasone 8 mg plus gentamicin 80 mg (group A), and oral administration of Cistiquer (group B) for 7 weeks. Before and after the therapeutic protocol, symptoms were assessed by three days voiding diary, the overactive bladder questionnaire short form and a ten points visual analogic scale adopted to assess the micturition discomfort. Histologic findings were assessed by the examination of specimens obtained by cold bladder biopsies of the bladder trigone at baseline in all the subjects. RESULTS: The two groups had significant and comparable symptoms improvement. However, the score obtained from the visual analogic scale decreased significantly only in the group submitted to oral therapy. Furthermore, in the group treated with endovesical approach, higher drop out rate and higher incidence of urinary infection were observed. CONCLUSION: Patients with urethral syndrome and trigonitis improved symptoms either with oral therapy with Cistiquer and with intra-vesical administration of gentamicin plus betametasone. However, treatment adherence resulted higher for patients treated by oral therapy and rate of adverse events resulted higher for those submitted to endovesical treatment.


Assuntos
Bromelaínas/uso terapêutico , Condroitina/uso terapêutico , Sintomas do Trato Urinário Inferior/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Quercetina/uso terapêutico , Doenças Uretrais/tratamento farmacológico , Adulto , Betametasona/uso terapêutico , Quimioterapia Combinada , Feminino , Gentamicinas/uso terapêutico , Glucocorticoides/uso terapêutico , Humanos , Sintomas do Trato Urinário Inferior/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Inquéritos e Questionários , Síndrome , Doenças Uretrais/complicações
9.
Opt Express ; 20(18): 20582-98, 2012 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-23037106

RESUMO

Elucidating the neural pathways that underlie brain function is one of the greatest challenges in neuroscience. Light sheet based microscopy is a cutting edge method to map cerebral circuitry through optical sectioning of cleared mouse brains. However, the image contrast provided by this method is not sufficient to resolve and reconstruct the entire neuronal network. Here we combined the advantages of light sheet illumination and confocal slit detection to increase the image contrast in real time, with a frame rate of 10 Hz. In fact, in confocal light sheet microscopy (CLSM), the out-of-focus and scattered light is filtered out before detection, without multiple acquisitions or any post-processing of the acquired data. The background rejection capabilities of CLSM were validated in cleared mouse brains by comparison with a structured illumination approach. We show that CLSM allows reconstructing macroscopic brain volumes with sub-cellular resolution. We obtained a comprehensive map of Purkinje cells in the cerebellum of L7-GFP transgenic mice. Further, we were able to trace neuronal projections across brain of thy1-GFP-M transgenic mice. The whole-brain high-resolution fluorescence imaging assured by CLSM may represent a powerful tool to navigate the brain through neuronal pathways. Although this work is focused on brain imaging, the macro-scale high-resolution tomographies affordable with CLSM are ideally suited to explore, at micron-scale resolution, the anatomy of different specimens like murine organs, embryos or flies.


Assuntos
Encéfalo/anatomia & histologia , Aumento da Imagem/instrumentação , Iluminação/instrumentação , Microscopia Confocal/instrumentação , Microscopia Confocal/veterinária , Animais , Desenho de Equipamento , Análise de Falha de Equipamento , Camundongos , Camundongos Transgênicos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
10.
Nat Commun ; 13(1): 15, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013203

RESUMO

New facilities such as the National Ignition Facility and the Linac Coherent Light Source have pushed the frontiers of high energy-density matter. These facilities offer unprecedented opportunities for exploring extreme states of matter, ranging from cryogenic solid-state systems to hot, dense plasmas, with applications to inertial-confinement fusion and astrophysics. However, significant gaps in our understanding of material properties in these rapidly evolving systems still persist. In particular, non-equilibrium transport properties of strongly-coupled Coulomb systems remain an open question. Here, we study ion-ion temperature relaxation in a binary mixture, exploiting a recently-developed dual-species ultracold neutral plasma. We compare measured relaxation rates with atomistic simulations and a range of popular theories. Our work validates the assumptions and capabilities of the simulations and invalidates theoretical models in this regime. This work illustrates an approach for precision determinations of detailed material properties in Coulomb mixtures across a wide range of conditions.

11.
Neuropharmacology ; 203: 108883, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34785165

RESUMO

Earlier studies have shown a major involvement of Ventral Tegmental Area (VTA) dopamine (DA) neurons in mediating the rewarding effects of ethanol (EtOH). Much less is known on the role of this system in mediating the transition from moderate to excessive drinking and abuse. Here we sought to explore the hypothesis that early stage drinking in rodents, resembling recreational EtOH use in humans, is sufficient to dysregulate VTA DA transmission thus increasing the propensity to use over time. To this purpose, midbrain slice recordings in mice previously exposed to an escalating (3, 6 and 12%) 18-day voluntary EtOH drinking paradigm was used. By recording from DA and γ-aminobutyric acid (GABA) VTA neurons in midbrain slices, we found that moderate EtOH drinking leads to a significant suppression of the spontaneous activity of VTA DA neurons, while increasing their response to acute EtOH application. We also found that chronic EtOH leads to the enhancement of GABA input frequency onto a subset of DA neurons. Structurally, chronic EtOH induced a significant increase in the number of GABA axonal boutons contacting DA neurons, suggesting deep rewiring of the GABA network. This scenario is consistent with a downmodulation of the reward DA system induced by moderate EtOH drinking, a neurochemical state defined as "hypodopaminergic" and previously associated with advanced stages of drug use in humans. In this context, increased sensitivity of DA neurons towards acute EtOH may represent the neurophysiological correlate of increased unitary rewarding value, possibly driving progression to addiction.


Assuntos
Consumo de Bebidas Alcoólicas/metabolismo , Neurônios Dopaminérgicos/metabolismo , Etanol/administração & dosagem , Neurônios GABAérgicos/metabolismo , Transmissão Sináptica/fisiologia , Área Tegmentar Ventral/metabolismo , Animais , Neurônios Dopaminérgicos/efeitos dos fármacos , Feminino , Neurônios GABAérgicos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Transgênicos , Técnicas de Cultura de Órgãos , Transmissão Sináptica/efeitos dos fármacos , Área Tegmentar Ventral/efeitos dos fármacos
12.
Syst Parasitol ; 80(2): 137-40, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21898202

RESUMO

Species of Philornis Meinert, 1890 (Diptera, Muscidae) are Neotropical dipterans that include species with parasitic larvae which feed on nestling birds. To date, all Philornis species that have been recorded from Argentina have parasitic subcutaneous larvae. Here, for the first time for Argentina, we report the finding of Philornis downsi Dodge & Aitken, 1968, a fly with a nest-dwelling, semi-haematophagous larva. This record, from the humid Chaco ecoregion of Argentina in the nest of a saffron finch Sicalis flaveola pelzelni Sclater, substantially extends the known distribution of this species. We also report the consensus sequences of the internal transcribed spacer 1 (ITS1) and ITS2 regions of three of the specimens for future reference and comparison. Further investigation is needed to determine whether Argentina is part of the historical range of P. downsi or, alternatively, represents a recent expansion of its range, perhaps due to climatic changes or other factors of global environmental variation.


Assuntos
Doenças das Aves/parasitologia , Tentilhões/parasitologia , Muscidae/classificação , Miíase/veterinária , Animais , Argentina/epidemiologia , Doenças das Aves/epidemiologia , Sequência Consenso , DNA Espaçador Ribossômico/genética , Larva/crescimento & desenvolvimento , Dados de Sequência Molecular , Muscidae/genética , Muscidae/crescimento & desenvolvimento , Miíase/epidemiologia , Miíase/parasitologia , Comportamento de Nidação , Análise de Sequência de DNA
13.
J Exp Med ; 160(5): 1375-89, 1984 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-6436431

RESUMO

We have shown previously that an activity which is capable of precipitating purified C1q and inhibiting some of the C1q-dependent biologic reactions could be solubilized from the membranes of both normal human peripheral B lymphocytes and a B cell-derived lymphoblastoid cell line (Raji), both of which are known to possess receptors for human C1q. In this report we present evidence that this membrane-associated C1q inhibitor is a chondroitinase-insensitive macromolecule and is the receptor for human C1q. The receptor was solubilized from membranes of Raji cells with Nonidet P-40 and purified to homogeneity using C1q-Sepharose 4B affinity chromatography. Equilibrium density gradient centrifugation analysis revealed that the complex could be resolved into a protein-rich, low density fraction and a carbohydrate-rich, high density fraction. The large hydrodynamic size, coupled with the high buoyant density, suggests that a proteoglycan is a constituent of the complex and indicates that the receptor might be a macromolecular complex of a proteoglycan portion noncovalently linked to a 60-70 kD glycoprotein. The glycoprotein moiety, in turn, consists of two or more identical (70,000 mol wt) polypeptide chains held together by disulfide bonds and constitutes the C1q receptor (C1qR). Sucrose density ultracentrifugation analysis showed that the isolated receptor sediments with an apparent rate of 4.2 S. Immunochemical analyses demonstrated that a typical preparation of the C1qR complex consists of approximately 23% uronic acid and approximately 21% galactosamine with a galactosamine-to-glucosamine ratio of 3.2. Binding of C1q to the receptor was found to be optimal at low ionic strength and neutral or near-neutral pH (7-7.4). The isolated receptor was found to inhibit C1q hemolytic function, abrogate C1q-dependent rosette formation, and block the C1q-dependent, cell-mediated cytotoxicity, all of which are activities mediated by the receptor.


Assuntos
Enzimas Ativadoras do Complemento/imunologia , Proteínas Inativadoras do Complemento/fisiologia , Receptores de Hialuronatos , Glicoproteínas de Membrana , Proteínas de Membrana/metabolismo , Receptores de Complemento/isolamento & purificação , Aminoácidos/análise , Ligação Competitiva , Linfoma de Burkitt/imunologia , Proteínas de Transporte , Linhagem Celular , Centrifugação com Gradiente de Concentração , Cromatografia de Afinidade , Enzimas Ativadoras do Complemento/metabolismo , Complemento C1q , Eletroforese em Gel de Poliacrilamida , Humanos , Imunodifusão , Proteínas Mitocondriais , Receptores de Complemento/análise , Receptores de Complemento/fisiologia
18.
Curr Top Microbiol Immunol ; 309: 169-87, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16909900

RESUMO

The rotaviruses, members of the family Reoviridae, are icosahedral triple-layered viruses with genomes consisting of 11 segments of double-stranded (ds)RNA. A characteristic feature of rotavirus-infected cells is the formation of large cytoplasmic inclusion bodies, termed viroplasms. These dynamic and highly organized structures serve as viral factories that direct the packaging and replication of the viral genome into early capsid assembly intermediates. Migration of the intermediates to the endoplasmic reticulum (ER) initiates a budding process that culminates in final capsid assembly. Recent information on the development and organization of viroplasms, the structure and function of its components, and interactive pathways linking RNA synthesis and capsid assembly provide new insight into how these microenvironments serve to interface the replication and morphogenetic processes of the virus.


Assuntos
Genoma Viral , Morfogênese , RNA Viral/biossíntese , Rotavirus/crescimento & desenvolvimento , Rotavirus/genética , Replicação Viral , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/fisiologia , Proteínas não Estruturais Virais/química , Proteínas não Estruturais Virais/fisiologia , Proteínas Virais/química , Proteínas Virais/fisiologia
19.
J Hosp Infect ; 65(3): 187-203, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17244516

RESUMO

A systematic review and meta-analysis of randomized controlled trials (RCTs) of selective decontamination of the digestive tract (SDD) was undertaken to evaluate the impact of this procedure on bacterial bloodstream infection and mortality. Data sources were Medline, Embase, Cochrane Register of Controlled Trials, previous meta-analyses, and conference proceedings, without restriction of language or publication status. RCTs were retrieved that compared oropharyngeal and/or intestinal administration of antibiotics as part of the SDD protocol, with or without a parenteral component, with no treatment or placebo in the controls. The three outcome measures were patients with bloodstream infection, causative micro-organisms, and total mortality. Fifty-one RCTs conducted between 1987 and 2005, comprising 8065 critically ill patients were included in the review; 4079 patients received SDD and 3986 were controls. SDD significantly reduced overall bloodstream infections [odds ratio (OR), 0.73; 95% confidence interval (CI), 0.59-0.90; P=0.0036], gram-negative bloodstream infections (OR, 0.39; 95% CI, 0.24-0.63; P<0.001) and overall mortality (OR, 0.80; 95% CI, 0.69-0.94; P=0.0064), without affecting gram-positive bloodstream infections (OR, 1.06; 95% CI, 0.77-1.47). The subgroup analysis showed an even larger impact of SDD using parenteral and enteral antimicrobials on overall bloodstream infections, bloodstream infections due to gram-negative bacteria and overall mortality with ORs of 0.63 (95% CI, 0.46-0.87; P=0.005), 0.30 (95% CI, 0.16-0.56; P<0.001), and 0.74 (95% CI, 0.61-0.91; P=0.0034), respectively. Twenty patients need to be treated with SDD to prevent one gram-negative bloodstream infection and 22 patients to prevent one death.


Assuntos
Antibacterianos/uso terapêutico , Antibioticoprofilaxia , Antifúngicos/uso terapêutico , Bacteriemia , Infecção Hospitalar/prevenção & controle , Descontaminação/métodos , Bacteriemia/microbiologia , Bacteriemia/mortalidade , Bacteriemia/prevenção & controle , Estado Terminal/mortalidade , Estado Terminal/terapia , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/microbiologia , Trato Gastrointestinal/microbiologia , Humanos , Controle de Infecções/métodos , Unidades de Terapia Intensiva , Ensaios Clínicos Controlados Aleatórios como Assunto
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA