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1.
Arch Argent Pediatr ; 118(2): 117-124, 2020 04.
Artículo en Inglés, Español | MEDLINE | ID: mdl-32199046

RESUMEN

INTRODUCTION: The assessment of growth during childhood and adolescence is a critical component of health care at all levels, but it is also part of nutritional status diagnosis and the timely detection of related conditions. Ecuador lacks national growth references, so it has decided to adopt the international standards proposed by the World Health Organization. The objective of this study was to develop national references for weight, height, and body mass index for children and adolescents. METHODS: Ecuadorian schoolchildren and adolescents aged 5-19 years were studied between 1999 and 2012. The LMS method for cross-sectional data, which uses the Box-Cox transformation to normalize data distribution at each age, was applied to estimate the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th centiles for weight, height, and body mass index. RESULTS: A total of 5934 healthy subjects (2788 boys and 3146 girls) participated. Boys were heavier and taller than girls. In all cases, values increased with age. At 18 years old, the differences between sexes averaged 8 kg and 12.5 cm. CONCLUSION: The tables and curves obtained with this study are the first descriptive growth references for Ecuadorian children and adolescents aged 5-19 years. They are relevant for nutritional assessment. Their use at the primary level of care will aid in nutritional status diagnosis, which has traditionally been done based on the World Health Organization's international standards.

2.
J Evid Based Med ; 12(2): 113-124, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30511477

RESUMEN

BACKGROUND: Red blood cell (RBC) transfusions are essential in health care. The quality of recommendations included in clinical practice guidelines (CPG), regarding this intervention, has not been systematically evaluated. This paper systematically assessed CPGs for RBC-transfusion, to appraise their methodological quality, to explore changes in quality over time, and to assess the consistency of the hemoglobin threshold (HT) recommendations. METHODS: We searched for CPGs that included recommendations of RBC-transfusion in generic databases, compiler entities, registries, clearinghouses and guideline developers. Three reviewers extracted data on CPGs characteristics and HT recommendations, independently appraised the quality of the studies using AGREE II and resolved disagreements by consensus. RESULTS: We examined 16 CPGs. Mean scores (mean ± SD) were: scope and purpose (59.4% ± 19.8%), stakeholder involvement (43.2% ± 22.6%), rigor of development (50% ± 25%), clarity of presentation (74.4% ± 12.6%), applicability (19.4% ± 18.8%), and editorial independence (41% ± 30%). Seven CPGs recommended a restrictive strategy for RBC transfusion; four CPGs gave a guarded statement considering an HT of 7 g/dL, as safe to prescribe an RBC transfusion. Eight CPGs did not provide an HT stating that RBC transfusions should not be prescribed by HT alone. CONCLUSIONS: Only 3 out of the 16 evaluated CPGs were "recommended" by the independent evaluators. Four domains "stakeholder involvement," "rigor of development," applicability," and "editorial independence" had serious shortcomings. Recommendations about the use of an HT for RBC-transfusion were heterogeneous among guidelines. Greater efforts are needed to provide high-quality CPGs in the RBC-transfusion practice.


Asunto(s)
Transfusión de Eritrocitos , Guías de Práctica Clínica como Asunto/normas , Políticas Editoriales , Hemoglobinas/metabolismo , Humanos , Participación de los Interesados
3.
Cochrane Database Syst Rev ; 6: CD009567, 2018 06 30.
Artículo en Inglés | MEDLINE | ID: mdl-29959871

RESUMEN

BACKGROUND: Acute high altitude illness is defined as a group of cerebral and pulmonary syndromes that can occur during travel to high altitudes. It is more common above 2500 metres, but can be seen at lower elevations, especially in susceptible people. Acute high altitude illness includes a wide spectrum of syndromes defined under the terms 'acute mountain sickness' (AMS), 'high altitude cerebral oedema' and 'high altitude pulmonary oedema'. There are several interventions available to treat this condition, both pharmacological and non-pharmacological; however, there is a great uncertainty regarding their benefits and harms. OBJECTIVES: To assess the clinical effectiveness, and safety of interventions (non-pharmacological and pharmacological), as monotherapy or in any combination, for treating acute high altitude illness. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, LILACS, ISI Web of Science, CINAHL, Wanfang database and the World Health Organization International Clinical Trials Registry Platform for ongoing studies on 10 August 2017. We did not apply any language restriction. SELECTION CRITERIA: We included randomized controlled trials evaluating the effects of pharmacological and non-pharmacological interventions for individuals suffering from acute high altitude illness: acute mountain sickness, high altitude pulmonary oedema or high altitude cerebral oedema. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the eligibility of study reports, the risk of bias for each and performed the data extraction. We resolved disagreements through discussion with a third author. We assessed the quality of evidence with GRADE. MAIN RESULTS: We included 13 studies enrolling a total of 468 participants. We identified two ongoing studies. All studies included adults, and two studies included both teenagers and adults. The 13 studies took place in high altitude areas, mostly in the European Alps. Twelve studies included participants with acute mountain sickness, and one study included participants with high altitude pulmonary oedema. Follow-up was usually less than one day. We downgraded the quality of the evidence in most cases due to risk of bias and imprecision. We report results for the main comparisons as follows.Non-pharmacological interventions (3 studies, 124 participants)All-cause mortality and complete relief of AMS symptoms were not reported in the three included trials. One study in 64 participants found that a simulated descent of 193 millibars versus 20 millibars may reduce the average of symptoms to 2.5 vs 3.1 units after 12 hours of treatment (clinical score ranged from 0 to 11 ‒ worse; reduction of 0.6 points on average with the intervention; low quality of evidence). In addition, no complications were found with use of hyperbaric chambers versus supplementary oxygen (one study; 29 participants; low-quality evidence).Pharmacological interventions (11 trials, 375 participants)All-cause mortality was not reported in the 11 included trials. One trial found a greater proportion of participants with complete relief of AMS symptoms after 12 and 16 hours when dexamethasone was administered in comparison with placebo (47.1% versus 0%, respectively; one study; 35 participants; low quality of evidence). Likewise, when acetazolamide was compared with placebo, the effects on symptom severity was uncertain (standardized mean difference (SMD) -1.15, 95% CI -2.56 to 0.27; 2 studies, 25 participants; low-quality evidence). One trial of dexamethasone in comparison with placebo in 35 participants found a reduction in symptom severity (difference on change in the AMS score: 3.7 units reported by authors; moderate quality of evidence). The effects from two additional trials comparing gabapentin with placebo and magnesium with placebo on symptom severity at the end of treatment were uncertain. For gabapentin versus placebo: mean visual analogue scale (VAS) score of 2.92 versus 4.75, respectively; 24 participants; low quality of evidence. For magnesium versus placebo: mean scores of 9 and 10.3 units, respectively; 25 participants; low quality of evidence). The trials did not find adverse events from either treatment (low quality of evidence). One trial comparing magnesium sulphate versus placebo found that flushing was a frequent event in the magnesium sulphate arm (percentage of flushing: 75% versus 7.7%, respectively; one study; 25 participants; low quality of evidence). AUTHORS' CONCLUSIONS: There is limited available evidence to determine the effects of non-pharmacological and pharmacological interventions in treating acute high altitude illness. Low-quality evidence suggests that dexamethasone and acetazolamide might reduce AMS score compared to placebo. However, the clinical benefits and harms related to these potential interventions remain unclear. Overall, the evidence is of limited practical significance in the clinical field. High-quality research in this field is needed, since most trials were poorly conducted and reported.


Asunto(s)
Mal de Altura/terapia , Acetazolamida/uso terapéutico , Enfermedad Aguda , Adolescente , Adulto , Aminas/uso terapéutico , Anticonvulsivantes/uso terapéutico , Presión Atmosférica , Ácidos Ciclohexanocarboxílicos/uso terapéutico , Dexametasona/uso terapéutico , Gabapentina , Glucocorticoides/uso terapéutico , Humanos , Hipertensión Pulmonar/terapia , Magnesio/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto , Ácido gamma-Aminobutírico/uso terapéutico
4.
J Vis Exp ; (130)2017 12 04.
Artículo en Inglés | MEDLINE | ID: mdl-29286464

RESUMEN

Understanding the chemistry of redox proteins demands methods that provide precise control over redox centers within the protein. The technique of protein film electrochemistry, in which a protein is immobilized on an electrode surface such that the electrode replaces physiological electron donors or acceptors, has provided functional insight into the redox reactions of a range of different proteins. Full chemical understanding requires electrochemical control to be combined with other techniques that can add additional structural and mechanistic insight. Here we demonstrate a technique, protein film infrared electrochemistry, which combines protein film electrochemistry with infrared spectroscopic sampling of redox proteins. The technique uses a multiple-reflection attenuated total reflectance geometry to probe a redox protein immobilized on a high surface area carbon black electrode. Incorporation of this electrode into a flow cell allows solution pH or solute concentrations to be changed during measurements. This is particularly powerful in addressing redox enzymes, where rapid catalytic turnover can be sustained and controlled at the electrode allowing spectroscopic observation of long-lived intermediate species in the catalytic mechanism. We demonstrate the technique with experiments on E. coli hydrogenase 1 under turnover (H2 oxidation) and non-turnover conditions.


Asunto(s)
Electroquímica/métodos , Hidrógeno/química , Hidrogenasas/química , Proteínas/química , Oxidación-Reducción
7.
Cochrane Database Syst Rev ; 5: CD002190, 2017 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-28516442

RESUMEN

BACKGROUND: The common cold is a spontaneously remitting infection of the upper respiratory tract, characterised by a runny nose, nasal congestion, sneezing, cough, malaise, sore throat, and fever (usually < 37.8º C). The widespread morbidity caused by the common cold worldwide is related to its ubiquitousness rather than its severity. The development of vaccines for the common cold has been difficult because of antigenic variability of the common cold virus and the indistinguishable multiple other viruses and even bacteria acting as infective agents. There is uncertainty regarding the efficacy and safety of interventions for preventing the common cold in healthy people. This is an update of a Cochrane review first published in 2011 and previously updated in 2013. OBJECTIVES: To assess the clinical effectiveness and safety of vaccines for preventing the common cold in healthy people. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (September 2016), MEDLINE (1948 to September 2016), Embase (1974 to September 2016), CINAHL (1981 to September 2016), and LILACS (1982 to September 2016). We also searched three trials registers for ongoing studies and four websites for additional trials (February 2017). We included no language or date restrictions. SELECTION CRITERIA: Randomised controlled trials (RCTs) of any virus vaccines compared with placebo to prevent the common cold in healthy people. DATA COLLECTION AND ANALYSIS: Two review authors independently evaluated methodological quality and extracted trial data. We resolved disagreements by discussion or by consulting a third review author. MAIN RESULTS: We found no additional RCTs for inclusion in this update. This review includes one RCT dating from the 1960s with an overall high risk of bias. The RCT included 2307 healthy participants, all of whom were included in analyses. This trial compared the effect of an adenovirus vaccine against placebo. No statistically significant difference in common cold incidence was found: there were 13 (1.14%) events in 1139 participants in the vaccines group and 14 (1.19%) events in 1168 participants in the placebo group (risk ratio 0.95, 95% confidence interval 0.45 to 2.02; P = 0.90). No adverse events related to the live vaccine were reported. The quality of the evidence was low due to limitations in methodological quality and a wide 95% confidence interval. AUTHORS' CONCLUSIONS: This Cochrane Review was based on one study with low-quality evidence. We found no conclusive results to support the use of vaccines for preventing the common cold in healthy people compared with placebo. We identified a need for well-designed, adequately powered RCTs to investigate vaccines for the common cold in healthy people. Any future trials on medical treatments for preventing the common cold should assess a variety of virus vaccines for this condition. Outcome measures should include common cold incidence, vaccine safety, and mortality related to the vaccine.


Asunto(s)
Vacunas contra el Adenovirus/administración & dosificación , Resfriado Común/prevención & control , Estado de Salud , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Vacunas Atenuadas/administración & dosificación
8.
ACS Catal ; 7(4): 2471-2485, 2017 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-28413691

RESUMEN

Catalysis of H2 production and oxidation reactions is critical in renewable energy systems based around H2 as a clean fuel, but the present reliance on platinum-based catalysts is not sustainable. In nature, H2 is oxidized at minimal overpotential and high turnover frequencies at [NiFe] catalytic sites in hydrogenase enzymes. Although an outline mechanism has been established for the [NiFe] hydrogenases involving heterolytic cleavage of H2 followed by a first and then second transfer of a proton and electron away from the active site, details remain vague concerning how the proton transfers are facilitated by the protein environment close to the active site. Furthermore, although [NiFe] hydrogenases from different organisms or cellular environments share a common active site, they exhibit a broad range of catalytic characteristics indicating the importance of subtle changes in the surrounding protein in controlling their behavior. Here we review recent time-resolved infrared (IR) spectroscopic studies and IR spectroelectrochemical studies carried out in situ during electrocatalytic turnover. Additionally, we re-evaluate the significant body of IR spectroscopic data on hydrogenase active site states determined through more conventional solution studies, in order to highlight mechanistic steps that seem to apply generally across the [NiFe] hydrogenases, as well as steps which so far seem limited to specific groups of these enzymes. This analysis is intended to help focus attention on the key open questions where further work is needed to assess important aspects of proton and electron transfer in the mechanism of [NiFe] hydrogenases.

9.
Anal Chem ; 88(13): 6666-71, 2016 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-27269716

RESUMEN

We describe a method for addressing redox enzymes adsorbed on a carbon electrode using synchrotron infrared microspectroscopy combined with protein film electrochemistry. Redox enzymes have high turnover frequencies, typically 10-1000 s(-1), and therefore, fast experimental triggers are needed in order to study subturnover kinetics and identify the involvement of transient species important to their catalytic mechanism. In an electrochemical experiment, this equates to the use of microelectrodes to lower the electrochemical cell constant and enable changes in potential to be applied very rapidly. We use a biological cofactor, flavin mononucleotide, to demonstrate the power of synchrotron infrared microspectroscopy relative to conventional infrared methods and show that vibrational spectra with good signal-to-noise ratios can be collected for adsorbed species with low surface coverages on microelectrodes with a geometric area of 25 × 25 µm(2). We then demonstrate the applicability of synchrotron infrared microspectroscopy to adsorbed proteins by reporting potential-induced changes in the flavin mononucleotide active site of a flavoenzyme. The method we describe will allow time-resolved spectroscopic studies of chemical and structural changes at redox sites within a variety of proteins under precise electrochemical control.


Asunto(s)
Técnicas Electroquímicas , Mononucleótido de Flavina/química , Espectrofotometría Infrarroja , Biocatálisis , Dominio Catalítico , Electrodos , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Oxidación-Reducción , Quinona Reductasas/química , Quinona Reductasas/metabolismo , Hollín/química , Sincrotrones
10.
Health Info Libr J ; 32(4): 276-86, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26192997

RESUMEN

OBJECTIVES: Journals in languages other than English that publish original clinical research are often not well covered in the main biomedical databases and therefore often not included in systematic reviews. This study aimed to identify Spanish language biomedical journals from Spain and Latin America and to describe their main features. METHODS: Journals were identified in electronic databases, publishers' catalogues and local registries. Eligibility was determined by assessing data from these sources or the journals' websites, when available. FINDINGS: A total of 2457 journals were initially identified; 1498 met inclusion criteria. Spain (27.3%), Mexico (16.0%), Argentina (15.1%) and Chile (11.9%) had the highest number of journals. Most (85.8%) are currently active; 87.8% have an ISSN. The median and mean length of publication were 22 and 29 years, respectively. A total of 66.0% were indexed in at least one database; 3.0% had an impact factor in 2012. A total of 845 journals had websites (56.4%), of which 700 (82.8%) were searchable and 681 (80.6%) free of charge. CONCLUSIONS: Most of the identified journals have no impact factor or are not indexed in any of the major databases. The list of identified biomedical journals can be a useful resource when conducting hand searching activities and identifying clinical trials that otherwise would not be retrieved.


Asunto(s)
Bases de Datos Bibliográficas/provisión & distribución , Lenguaje , Edición/tendencias , Humanos , Factor de Impacto de la Revista , América Latina , Edición/provisión & distribución , Investigación/estadística & datos numéricos , España
11.
J Am Chem Soc ; 137(26): 8484-9, 2015 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-26103582

RESUMEN

Despite extensive studies on [NiFe]-hydrogenases, the mechanism by which these enzymes produce and activate H2 so efficiently remains unclear. A well-known EPR-active state produced under H2 and known as Ni-C is assigned as a Ni(III)-Fe(II) species with a hydrido ligand in the bridging position between the two metals. It has long been known that low-temperature photolysis of Ni-C yields distinctive EPR-active states, collectively termed Ni-L, that are attributed to migration of the bridging-H species as a proton; however, Ni-L has mainly been regarded as an artifact with no mechanistic relevance. It is now demonstrated, based on EPR and infrared spectroscopic studies, that the Ni-C to Ni-L interconversion in Hydrogenase-1 (Hyd-1) from Escherichia coli is a pH-dependent process that proceeds readily in the dark-proton migration from Ni-C being favored as the pH is increased. The persistence of Ni-L in Hyd-1 must relate to unassigned differences in proton affinities of metal and adjacent amino acid sites, although the unusually high reduction potentials of the adjacent Fe-S centers in this O2-tolerant hydrogenase might also be a contributory factor, impeding elementary electron transfer off the [NiFe] site after proton departure. The results provide compelling evidence that Ni-L is a true, albeit elusive, catalytic intermediate of [NiFe]-hydrogenases.


Asunto(s)
Carbono/química , Proteínas de Escherichia coli/química , Hidrogenasas/química , Nitrógeno/química , Dominio Catalítico , Espectroscopía de Resonancia por Spin del Electrón , Electrones , Escherichia coli/enzimología , Hidrógeno/química , Concentración de Iones de Hidrógeno , Ligandos , Metales/química , Níquel/química , Oxidación-Reducción , Oxígeno/química , Fotólisis , Protones , Temperatura
12.
Angew Chem Int Ed Engl ; 54(24): 7110-3, 2015 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-25925315

RESUMEN

A novel in situ IR spectroscopic approach is demonstrated for the characterization of hydrogenase during catalytic turnover. E. coli hydrogenase 1 (Hyd-1) is adsorbed on a high surface-area carbon electrode and subjected to the same electrochemical control and efficient supply of substrate as in protein film electrochemistry during spectral acquisition. The spectra reveal that the active site state known as Ni-L, observed in other NiFe hydrogenases only under illumination or at cryogenic temperatures, can be generated reversibly in the dark at ambient temperature under both turnover and non-turnover conditions. The observation that Ni-L is present at all potentials during turnover under H2 suggests that the final steps in the catalytic cycle of H2 oxidation by Hyd-1 involve sequential proton and electron transfer via Ni-L. A broadly applicable IR spectroscopic technique is presented for addressing electrode-adsorbed redox enzymes under fast catalytic turnover.


Asunto(s)
Hidrógeno/química , Hidrogenasas/metabolismo , Níquel/química , Biocatálisis , Dominio Catalítico , Técnicas Electroquímicas , Electrodos , Espectroscopía de Resonancia por Spin del Electrón , Transporte de Electrón , Escherichia coli/enzimología , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Hidrógeno/metabolismo , Hidrogenasas/química , Ligandos , Oxidación-Reducción , Protones , Espectrofotometría Infrarroja
13.
Dent. press implantol ; 8(4): 28-34, Oct.-Dec. 2014. ilus, tab
Artículo en Portugués | LILACS, BBO - Odontología | ID: lil-762302

RESUMEN

Objetivo: avaliar, por meio de uma revisão sistemática de literatura, a taxa de sobrevida de implantes osseointegráveis, em estudos longitudinais que realizaram um acompanhamento superior a 10 anos. Métodos: foi realizada uma ampla busca eletrônica — nas bases MEDLINE/PubMed, LILACS e Colaboração Cochrane — por publicações relevantes em revistas indexadas, publicadas a partir do ano de 1981, avaliando o desempenho clínico dos implantes. Usando critérios de inclusão e exclusão, dois revisores analisaram títulos, resumos e artigos completos, dando prioridade aos estudos controlados randomizados (RCTs). Resultados: no total, 16 artigos foram incluídos nessa revisão. Foram selecionados 6 estudos prospectivos, 7 estudos retrospectivos e 3 ensaios clínicos randomizados, que avaliaram 6.515 implantes, ao todo. A média do tempo de acompanhamento foi de 13,4 anos. Após as análises estatísticas, foi encontrada uma média cumulativa de sobrevivência de 95,5 ± 4,2% (n = 6.515). Conclusão: os resultados dessa revisão sistemática demonstraram que os implantes apresentam altas taxas de sobrevivência em longo prazo, desde que haja um correto planejamento e que os pacientes estejam incluídos em um criterioso programa de manutenção pós-tratamento.


Objective: To assess, by means of a systematic literature review, the survival rates of osseointegrated implants, in longitudinal studies with a follow-up exceeding 10 years.Methods: MEDLINE/PubMed, LILACS and Cochrane Collaboration were used to retrieve relevant publications published in indexed journals from the year 1981 on, and which assessed the clinical performance of implants. Based on previously established inclusion and exclusion criteria, two reviewers assessed titles, abstracts and full papers giving priority to randomized controlled trials (RCTs). Results: A total of 16 articles were included in this review. Six prospective studies, sevenretrospective studies and three randomized controlled trials, assessing 6,515 implants, were selected.The mean follow-up time was 13.4 years. Statistical analysis revealed a mean cumulative survival rate of 95.5 ± 4.2 (n = 6,515). Conclusion: The results of this systematic review revealed thatimplants have high success rates in the long-term, provided there is proper planning and patients are included in a thorough maintenance post-treatment program.


Asunto(s)
Implantación Dental , Tasa de Supervivencia , Brasil , Estudios Longitudinales
14.
Faraday Discuss ; 172: 473-96, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25426610

RESUMEN

We present a study of electrocatalysis by an enzyme adsorbed on a range of carbon materials, with different size, surface area, morphology and graphitic structure, which are either commercially available or prepared via simple, established protocols. We choose as our model enzyme the hydrogenase I from E. coli (Hyd-1), which is an active catalyst for H2 oxidation, is relatively robust and has been demonstrated in H2 fuel cells and H2-driven chemical synthesis. The carbon materials were characterised according to their surface area, surface morphology and graphitic character, and we use the electrocatalytic H2 oxidation current for Hyd-1 adsorbed on these materials to evaluate their effectiveness as enzyme electrodes. Here, we show that a variety of carbon materials are suitable for adsorbing hydrogenases in an electroactive configuration. This unified study provides insight into selection and design of carbon materials for study of redox enzymes and different applications of enzyme electrocatalysis.


Asunto(s)
Técnicas Electroquímicas , Proteínas de Escherichia coli/química , Hidrógeno/química , Nanotubos de Carbono/química , Oxidorreductasas/química , Catálisis , Escherichia coli/química , Escherichia coli/enzimología , Nanotubos de Carbono/clasificación , Oxidación-Reducción , Propiedades de Superficie
15.
Cochrane Database Syst Rev ; (6): CD002190, 2013 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-23757114

RESUMEN

BACKGROUND: The common cold is a spontaneously remitting infection of the upper respiratory tract, characterised by a runny nose, nasal congestion, sneezing, cough, malaise, sore throat and fever (usually < 37.8˚C). The widespread morbidity it causes worldwide is related to its ubiquitousness rather than its severity. The development of vaccines for the common cold has been difficult because of antigenic variability of the common cold virus and the indistinguishable multiple other viruses and even bacteria acting as infective agents. There is uncertainty regarding the efficacy and safety of interventions for preventing the common cold in healthy people. OBJECTIVES: To assess the clinical effectiveness and safety of vaccines for preventing the common cold in healthy people. SEARCH METHODS: We searched CENTRAL (2012, Issue 12), MEDLINE (1948 to January week 1, 2013), EMBASE (1974 to January 2013), CINAHL (1981 to January 2013) and LILACS (1982 to January 2013). SELECTION CRITERIA: Randomised controlled trials (RCTs) of any virus vaccines to prevent the common cold in healthy people. DATA COLLECTION AND ANALYSIS: Two review authors independently evaluated methodological quality and extracted trial data. Disagreements were resolved by discussion or by consulting a third review author. MAIN RESULTS: This review included one RCT with 2307 healthy participants; all of them were analysed. This trial compared the effect of an adenovirus vaccine against a placebo. No statistically significant difference in common cold incidence was found: there were 13 events in 1139 participants in the vaccines group and 14 events in 1168 participants in the placebo group; risk ratio (RR) 0.95, 95% confidence interval (CI) 0.45 to 2.02, P = 0.90). No adverse events related to the live vaccine were reported. AUTHORS' CONCLUSIONS: This Cochrane review has found a lack of evidence on the effects of vaccines for the common cold in healthy people. Only one RCT was found and this did not show differences between comparison groups; it also had a high risk of bias. There are no conclusive data to support the use of vaccines for preventing the common cold in healthy people. We identified the need for well-designed, adequately powered RCTs to investigate vaccines for the common cold in healthy people. Unless RCTs provide evidence of a treatment effect and the trade-off between potential benefits and harms is established, policy-makers, clinicians and academics should not recommend the use of vaccines for preventing the common cold in healthy people. Any future trials on medical treatments for preventing the common cold should assess a variety of virus vaccines for this condition. Outcome measures should include common cold incidence, vaccine safety and mortality related to the vaccine.


Asunto(s)
Vacunas contra el Adenovirus/administración & dosificación , Resfriado Común/prevención & control , Estado de Salud , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Vacunas Atenuadas/administración & dosificación
16.
Cochrane Database Syst Rev ; 11: CD009077, 2012 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-23152267

RESUMEN

BACKGROUND: Chagas disease-related cardiomyopathy is a major cause of morbidity and mortality in Latin America. Despite the substantial burden to the healthcare system, there is uncertainty regarding the efficacy and safety of pharmacological interventions for treating heart failure in patients with Chagas disease. OBJECTIVES: To assess the benefits and harms of current pharmacological interventions for treating heart failure in patients with Chagas cardiomyopathy. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library) Issue 1, 2011, MEDLINE (Ovid), EMBASE (Ovid), LILACS and ISI Web of Science to April 2011. We checked the reference lists of included papers. No language restrictions were applied. SELECTION CRITERIA: We included randomized clinical trials assessing the effects of pharmacological interventions for treating heart failure in adult patients (≥18 years) with symptomatic heart failure (New York Heart Association class II to IV), irrespective of the left ventricular ejection fraction stage, reduced or preserved, with Chagas cardiomyopathy. No limits were applied with respect to the follow-up duration. Primary outcomes were all-cause mortality, cardiovascular mortality at 30 days, time to heart decompensation and disease-free period (at 30, 60 and 90 days), and adverse events. DATA COLLECTION AND ANALYSIS: Two authors independently performed study selection, risk of bias assessment and data extraction. We estimated relative risks (RR) and the respective 95% confidence intervals (CIs) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a fixed-effect model to synthesize the findings. We contacted authors for additional data. MAIN RESULTS: We included two randomized clinical trials involving 69 participants. Both trials compared carvedilol against placebo, and had a high risk of bias. Carvedilol compared with placebo did not significantly affect all-cause mortality (2/34 (5.88%) versus 3/35 (5.87%); pooled RR 0.69, 95% CI 0.12 to 3.88, I(2) = 0%). None of the trials reported on cardiovascular mortality, time to heart decompensation or disease-free period. Evidence on the adverse effects of carvedilol is inconclusive. AUTHORS' CONCLUSIONS: This Cochrane review has found a lack of evidence on the effects of carvedilol for treating heart failure in patients with Chagas disease. The two included trials were underpowered and had a high risk of bias. There are no conclusive data to support the use of carvedilol for treating Chagas cardiomyopathy. Unless randomized clinical trials provide evidence of a treatment effect, and the trade off between potential benefits and harms is established, policy-makers, clinicians, and academics should be cautious when recommending and administering carvedilol for treating heart failure in patients with Chagas disease. The efficacy and safety of other pharmacological interventions for treating heart failure in patients with Chagas disease is unknown.


Asunto(s)
Carbazoles/uso terapéutico , Cardiotónicos/uso terapéutico , Cardiomiopatía Chagásica/complicaciones , Insuficiencia Cardíaca/tratamiento farmacológico , Propanolaminas/uso terapéutico , Adulto , Carbazoles/efectos adversos , Cardiotónicos/efectos adversos , Carvedilol , Insuficiencia Cardíaca/etiología , Humanos , Propanolaminas/efectos adversos , Ensayos Clínicos Controlados Aleatorios como Asunto
17.
Rev. bras. odontol ; 64(1/2): 8-12, 2007. ilus
Artículo en Portugués | LILACS, BBO - Odontología | ID: lil-541843

RESUMEN

O presente estudo teve como objetivo analisar, por meio do método de elemetos finitos, a influência do preparo cavitário e do material restaurador na distribuição de tensões em restaurações do tipo inlay. Sete modelos matemáticos bidimensionais foram criados a partir de uma imagem digitalizada de um primeiro molar inferior. A análise foi feita no programa Abaqus (HKS), utilizando-se uma carga estátística de 300N distribuídas em três regiões das superfícies oclusais dos modelos. Os resultados mostraram que o compósito laboratorial (cerômero) foi o que apresentou a melhor distribuição de tensões, gerando um padrão homogêneo das mesmas.


Asunto(s)
Análisis de Elementos Finitos , Cerámica , Ensayo de Materiales , Modelos Teóricos , Materiales de Obturación del Conducto Radicular , Preparación del Conducto Radicular , Diente Molar
20.
Rev. panam. salud pública ; 19(6): 417-422, jun. 2006. tab
Artículo en Inglés | LILACS | ID: lil-433462

RESUMEN

Debido a los sesgos que afectan a la publicación de ensayos clínicos y sus resultados, los estudios cuyos resultados son positivos son más fáciles de encontrar que los que tienen resultados sin significación estadística y a ello se debe que los primeros estén sobrerrepresentados. Para contrarrestar este tipo de sesgo se ha propuesto ingresar en un registro toda investigación, desde sus comienzos. No obstante, estos registros se encuentran en distintas fases de evolución, especialmente en países en desarrollo, de tal manera que la Red Cochrane Iberoamericana, parte de la Colaboración Cochrane, ha establecido el Registro Latinoamericano de Ensayos Clínicos en Curso (LATINREC, por Latin American Clinical Trial Registry) con la idea de facilitar el registro de los datos contenidos en el protocolo de todo ensayo clínico que se esté llevando a cabo en un momento dado y poner esa información a la disposición del público. El LATINREC, que viene a respaldar los objetivos de la Organización Mundial de la Salud (OMS), representa un intento por reducir la duplicación de trabajo y el financiamiento poco equitativo de la investigación sobre enfermedades rezagadas al olvido; por evitar que se efectúen investigaciones sobre asuntos de poca cuantía o que se midan resultados poco útiles; y por fomentar las prácticas éticas y la transparencia. Se han detectado algunos obstáculos mayores que hasta ahora han impedido crear un registro único y común de ensayos clínicos. Con el fin de franquearlos, LATINREC será un registro gratuito que permitirá hacer búsquedas y que se ceñirá a la Plataforma Internacional de Registro de Ensayos Clínicos (ICTRP) de la OMS. Además, LATINREC permitirá que los investigadores ingresen en el registro cualquier modificación del protocolo, así como los resultados preliminares. LATINREC ofrecerá grandes ventajas para los consumidores, el gobierno, los profesionales de la salud pública y la industria farmacéutica al incrementar la accesibilidad de la información y la participación en los ensayos clínicos. La disponibilidad de información objetiva acerca de todo ensayo clínico que se inicie ayudará a garantizar que todos tengan libre acceso a los conocimientos generados.


Asunto(s)
Ensayos Clínicos como Asunto , Sistema de Registros , América Latina , Sesgo de Publicación , Edición
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