924 resultados para Reservoir Selection Criteria
Resumo:
OBJECTIVE: To evaluate the relationship between changes in body bioelectrical impedance (BI) at 0.5, 50 and kHz and the changes in body weight, as an index of total body water changes, in acutely ill surgical patients during the rapid infusion of isotonic saline solution. DESIGN: Prospective clinical study. SETTING: Multidisciplinary surgical ICU in a university hospital. PATIENTS: Twelve male patients treated for acute surgical illness (multiple trauma n = 5, major surgery n = 7). Selection criteria: stable cardiovascular parameters, normal cardiac function, signs of hypovolemia (CVP < or = 5 mmHg, urine output < 1 ml/kg x h). INTERVENTIONS: After baseline measurements, a 60 min fluid challenge test was performed with normal saline solution, 0.25 ml/kg/min [corrected]. MEASUREMENTS AND RESULTS: Body weight (platform digital scale), total body impedance (four-surface electrode technique; measurements at 0.5, 50 and 100 kHz) and urine output. Fluid retention induced a progressive decrease in BI at 0.5, 50 and 100 kHz, but the changes were significant for BI 0.5 and BI 100 only, from 40 min after the beginning of the fluid therapy onwards. There was a significant negative correlation between changes in water retention and BI 0.5, with individual correlation coefficients ranging from -0.72 to 0.95 (p < 0.01-0.0001). The slopes of the regression lines indicated that for each kg of water change, there was a mean decrease in BI of 18 ohm, but a substantial inter-individual variability was noted. CONCLUSION: BI measured at low frequency can represent a valuable index of acute changes in body water in a group of surgical patients but not in a given individual.
Resumo:
Recent studies of relativistic jet sources in the Galaxy, also known as microquasars, have been very useful in trying to understand the accretion/ejection processes that take place near compact objects. However, the number of sources involved in such studies is still small. In an attempt to increase the number of known microquasars we have carried out a search for new Radio Emitting X-ray Binaries (REXBs). These sources are the ones to be observed later with VLBI techniques to unveil their possible microquasar nature. To this end, we have performed a cross-identification between the X-ray ROSAT all sky survey Bright Source Catalog (RBSC) and the radio NRAO VLA Sky Survey (NVSS) catalogs under very restrictive selection criteria for sources with |b|<5 degrees. We have also conducted a deep observational radio and optical study for six of the selected candidates. At the end of this process two of the candidates appear to be promising, and deserve additional observations aimed to confirm their proposed microquasar nature.
Resumo:
Lung transplantation has now been performed for more than 30 years in patients with end-stage chronic obstructive pulmonary disease (COPD). This disease is the major indication for lung transplantation, involving more than one third of the procedures worldwide. Although lung transplantation in COPD patients has clearly shown a positive impact on lung function, exercise capacity and quality of life, the survival benefit remains difficult to ascertain. Several methodological difficulties, particularly the absence of classical randomised studies, make the analysis especially challenging. There is however indirect but convincing evidence that lung transplantation can, when appropriate selection criteria are applied, provide not only an active post-transplant lifestyle but also a survival benefit for patients with COPD.
Resumo:
Analysis of information on the classification and indexing of the entire run of Biblioteconomía (1944-1976), the bulletin of the School of Librarians of Barcelona. Selection criteria included items directly related to the issue at hand, such as documental languages (classifications and subject heading lists) and subject catalogues (in both alphabetic and shelf order). Although the intention was to achieve a comprehensive analysis, priority was given to the importance and value of the information selected. Only those items considered to be significant within the chosen theme were chosen.
Resumo:
The goal of this paper is to provide clinicians and researchers, who may not be experts in psychometrics, with a guide for the selection and adaptation of an instrument for clinical research. Issues related to the concept to be measured, the targeted clientele, the selection criteria for the instrument (algorithm), the strategies for translation and adaptation, as well as potential bias related to the administration of an instrument are reviewed and discussed.
Resumo:
BACKGROUND: Several studies have established Glioblastoma Multiforme (GBM) prognostic and predictive models based on age and Karnofsky Performance Status (KPS), while very few studies evaluated the prognostic and predictive significance of preoperative MR-imaging. However, to date, there is no simple preoperative GBM classification that also correlates with a highly prognostic genomic signature. Thus, we present for the first time a biologically relevant, and clinically applicable tumor Volume, patient Age, and KPS (VAK) GBM classification that can easily and non-invasively be determined upon patient admission. METHODS: We quantitatively analyzed the volumes of 78 GBM patient MRIs present in The Cancer Imaging Archive (TCIA) corresponding to patients in The Cancer Genome Atlas (TCGA) with VAK annotation. The variables were then combined using a simple 3-point scoring system to form the VAK classification. A validation set (N = 64) from both the TCGA and Rembrandt databases was used to confirm the classification. Transcription factor and genomic correlations were performed using the gene pattern suite and Ingenuity Pathway Analysis. RESULTS: VAK-A and VAK-B classes showed significant median survival differences in discovery (P = 0.007) and validation sets (P = 0.008). VAK-A is significantly associated with P53 activation, while VAK-B shows significant P53 inhibition. Furthermore, a molecular gene signature comprised of a total of 25 genes and microRNAs was significantly associated with the classes and predicted survival in an independent validation set (P = 0.001). A favorable MGMT promoter methylation status resulted in a 10.5 months additional survival benefit for VAK-A compared to VAK-B patients. CONCLUSIONS: The non-invasively determined VAK classification with its implication of VAK-specific molecular regulatory networks, can serve as a very robust initial prognostic tool, clinical trial selection criteria, and important step toward the refinement of genomics-based personalized therapy for GBM patients.
Resumo:
Après avoir situé le contexte de la recherche et défini les enjeux principaux du travail, différents types de nanoparticules, ainsi que leurs principales caractéristiques, sont parcourues. L'élaboration de critères de sélection ayant permis de déterminer les types de nanoparticules potentiellement adaptés à !a détection de traces papillaires, l'étude s'est alors focalisée sur deux familles de composés: les quantum dots et les nanoparticules d'oxyde de silicium. Deux types de quantum dots ont été synthétisés : le tellurure de cadmium et le sulfure de zinc). Ils n'ont toutefois pas permis la détection de traces papillaires réalistes. En effet, seules des traces fraîches et enrichies en sécrétions ont pu être mises en évidence. Toutefois, des résultats ont été obtenus avec les deux types de quantum dots pour la détection de traces papillaires sanglantes. Après optimisation, les techniques rivalisent avec les méthodes couramment appliquées en routine. Cependant, l'interaction se produisant entre les traces et les nanoparticules n'a pas pu être déterminé. Les nanoparticules d'oxyde de silicium ont dès lors été appliquées dans le but de comprendre plus en détails les interactions avec les traces papillaires. Ces nanoparticules ont l'avantage d'offrir un très bon contrôle de surface, permettant ainsi une étude détaillée des phénomènes en jeu. Des propriétés de surface variables ont dès lors été obtenues en greffant diverses molécules à la surface des nanoparticules d'oxyde de silicium. Après avoir exploré différentes hypothèses d'interaction, il a pu être déterminé qu'une réaction chimique se produit lors qu'un groupement de type carboxyle est présent à la surface des particules. Ce groupement réagit avec les fonctions amines primaires des sécrétions. L'interaction chimique a ensuite pu être renforcée par l'utilisation d'un catalyseur, permettant d'accélérer la réaction. Dans la dernière partie du travail, les nanoparticules d'oxyde de silicium ont été comparées à une technique utilisée en routine, la fumigation de cyanoacrylate. Bien que des études plus approfondies soient nécessaires, il s'avère que l'application de nanoparticules d'oxyde de silicium permet une détection de très bonne qualité, moins dépendante du donneur que les techniques courantes. Ces résultats sont prometteurs en vue du développement d'une technique possédant une sensibilité et une sélectivité accrue. - Having situated the background of research and identified key issues of work, different types of nanoparticles and their main features are reviewed. The development of selection criteria lead to the identification of nanoparticles types potentially suitable for fingermarks detection. The study focused then On two families of compounds: quantum dots and silicon oxide nanoparticles. Two types of quantum dots were synthesized and characterised: cadmium telluride and zinc sulphide. Unfortunally, they did not allow the detection realistic fingermarks. Indeed, only fresh and groomed fingermarks have been detected. However, results have been obtained with both types of quantum dots for the detection of fingermarks in blood. After optimization procedures, the quantum dots based teshniques compete with the methods currently used in routine. However, the interaction occurring between fingermarks and nanoparticles could not be determined. Silicon oxide nanoparticles have therefore been applied in order to understand in detail the interactions With fingermarks. These nanoparticles have the advantage of providing a very good surface control, allowing am in-depth study of the phenomena involved. Versatile surface properties were therefore obtained by grafting various molecules on the surface of silicon oxide nanoparticles. Different hypotheses were investigated and it was determined that a chemical reaction occurred between the surface functionalised nanoparticles and the fingermark residues. The carboxyl groups on the surface of the particles react with primary amines of the secretions. Therefore, this interaction was improved by the use of a catalyst. In the last part of the work, silicon oxide nanoparticles were compared to a routinely used technique: cyanocrylate fuming. Although further studies are still needed, it appears that the application of silicon oxide nanoparticles allows fingermark detection of very good quality, with a lowered donor dependency. These results are promising for the development of techniques with greater sensitivity and selectivity.
Resumo:
BACKGROUND: Smoking contributes to reasons for hospitalisation, and the period of hospitalisation may be a good time to provide help with quitting. OBJECTIVES: To determine the effectiveness of interventions for smoking cessation that are initiated for hospitalised patients. SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group register which includes papers identified from CENTRAL, MEDLINE, EMBASE and PsycINFO in December 2011 for studies of interventions for smoking cessation in hospitalised patients, using terms including (hospital and patient*) or hospitali* or inpatient* or admission* or admitted. SELECTION CRITERIA: Randomized and quasi-randomized trials of behavioural, pharmacological or multicomponent interventions to help patients stop smoking, conducted with hospitalised patients who were current smokers or recent quitters (defined as having quit more than one month before hospital admission). The intervention had to start in the hospital but could continue after hospital discharge. We excluded studies of patients admitted to facilities that primarily treat psychiatric disorders or substance abuse, studies that did not report abstinence rates and studies with follow-up of less than six months. Both acute care hospitals and rehabilitation hospitals were included in this update, with separate analyses done for each type of hospital. DATA COLLECTION AND ANALYSIS: Two authors extracted data independently for each paper, with disagreements resolved by consensus. MAIN RESULTS: Fifty trials met the inclusion criteria. Intensive counselling interventions that began during the hospital stay and continued with supportive contacts for at least one month after discharge increased smoking cessation rates after discharge (risk ratio (RR) 1.37, 95% confidence interval (CI) 1.27 to 1.48; 25 trials). A specific benefit for post-discharge contact compared with usual care was found in a subset of trials in which all participants received a counselling intervention in the hospital and were randomly assigned to post-discharge contact or usual care. No statistically significant benefit was found for less intensive counselling interventions. Adding nicotine replacement therapy (NRT) to an intensive counselling intervention increased smoking cessation rates compared with intensive counselling alone (RR 1.54, 95% CI 1.34 to 1.79, six trials). Adding varenicline to intensive counselling had a non-significant effect in two trials (RR 1.28, 95% CI 0.95 to 1.74). Adding bupropion did not produce a statistically significant increase in cessation over intensive counselling alone (RR 1.04, 95% CI 0.75 to 1.45, three trials). A similar pattern of results was observed in a subgroup of smokers admitted to hospital because of cardiovascular disease (CVD). In this subgroup, intensive intervention with follow-up support increased the rate of smoking cessation (RR 1.42, 95% CI 1.29 to 1.56), but less intensive interventions did not. One trial of intensive intervention including counselling and pharmacotherapy for smokers admitted with CVD assessed clinical and health care utilization endpoints, and found significant reductions in all-cause mortality and hospital readmission rates over a two-year follow-up period. These trials were all conducted in acute care hospitals. A comparable increase in smoking cessation rates was observed in a separate pooled analysis of intensive counselling interventions in rehabilitation hospitals (RR 1.71, 95% CI 1.37 to 2.14, three trials). AUTHORS' CONCLUSIONS: High intensity behavioural interventions that begin during a hospital stay and include at least one month of supportive contact after discharge promote smoking cessation among hospitalised patients. The effect of these interventions was independent of the patient's admitting diagnosis and was found in rehabilitation settings as well as acute care hospitals. There was no evidence of effect for interventions of lower intensity or shorter duration. This update found that adding NRT to intensive counselling significantly increases cessation rates over counselling alone. There is insufficient direct evidence to conclude that adding bupropion or varenicline to intensive counselling increases cessation rates over what is achieved by counselling alone.
Resumo:
Measuring school efficiency is a challenging task. First, a performance measurement technique has to be selected. Within Data Envelopment Analysis (DEA), one such technique, alternative models have been developed in order to deal with environmental variables. The majority of these models lead to diverging results. Second, the choice of input and output variables to be included in the efficiency analysis is often dictated by data availability. The choice of the variables remains an issue even when data is available. As a result, the choice of technique, model and variables is probably, and ultimately, a political judgement. Multi-criteria decision analysis methods can help the decision makers to select the most suitable model. The number of selection criteria should remain parsimonious and not be oriented towards the results of the models in order to avoid opportunistic behaviour. The selection criteria should also be backed by the literature or by an expert group. Once the most suitable model is identified, the principle of permanence of methods should be applied in order to avoid a change of practices over time. Within DEA, the two-stage model developed by Ray (1991) is the most convincing model which allows for an environmental adjustment. In this model, an efficiency analysis is conducted with DEA followed by an econometric analysis to explain the efficiency scores. An environmental variable of particular interest, tested in this thesis, consists of the fact that operations are held, for certain schools, on multiple sites. Results show that the fact of being located on more than one site has a negative influence on efficiency. A likely way to solve this negative influence would consist of improving the use of ICT in school management and teaching. Planning new schools should also consider the advantages of being located on a unique site, which allows reaching a critical size in terms of pupils and teachers. The fact that underprivileged pupils perform worse than privileged pupils has been public knowledge since Coleman et al. (1966). As a result, underprivileged pupils have a negative influence on school efficiency. This is confirmed by this thesis for the first time in Switzerland. Several countries have developed priority education policies in order to compensate for the negative impact of disadvantaged socioeconomic status on school performance. These policies have failed. As a result, other actions need to be taken. In order to define these actions, one has to identify the social-class differences which explain why disadvantaged children underperform. Childrearing and literary practices, health characteristics, housing stability and economic security influence pupil achievement. Rather than allocating more resources to schools, policymakers should therefore focus on related social policies. For instance, they could define pre-school, family, health, housing and benefits policies in order to improve the conditions for disadvantaged children.
Resumo:
BACKGROUND: Clinical practice does not always reflect best practice and evidence, partly because of unconscious acts of omission, information overload, or inaccessible information. Reminders may help clinicians overcome these problems by prompting the doctor to recall information that they already know or would be expected to know and by providing information or guidance in a more accessible and relevant format, at a particularly appropriate time. OBJECTIVES: To evaluate the effects of reminders automatically generated through a computerized system and delivered on paper to healthcare professionals on processes of care (related to healthcare professionals' practice) and outcomes of care (related to patients' health condition). SEARCH METHODS: For this update the EPOC Trials Search Co-ordinator searched the following databases between June 11-19, 2012: The Cochrane Central Register of Controlled Trials (CENTRAL) and Cochrane Library (Economics, Methods, and Health Technology Assessment sections), Issue 6, 2012; MEDLINE, OVID (1946- ), Daily Update, and In-process; EMBASE, Ovid (1947- ); CINAHL, EbscoHost (1980- ); EPOC Specialised Register, Reference Manager, and INSPEC, Engineering Village. The authors reviewed reference lists of related reviews and studies. SELECTION CRITERIA: We included individual or cluster-randomized controlled trials (RCTs) and non-randomized controlled trials (NRCTs) that evaluated the impact of computer-generated reminders delivered on paper to healthcare professionals on processes and/or outcomes of care. DATA COLLECTION AND ANALYSIS: Review authors working in pairs independently screened studies for eligibility and abstracted data. We contacted authors to obtain important missing information for studies that were published within the last 10 years. For each study, we extracted the primary outcome when it was defined or calculated the median effect size across all reported outcomes. We then calculated the median absolute improvement and interquartile range (IQR) in process adherence across included studies using the primary outcome or median outcome as representative outcome. MAIN RESULTS: In the 32 included studies, computer-generated reminders delivered on paper to healthcare professionals achieved moderate improvement in professional practices, with a median improvement of processes of care of 7.0% (IQR: 3.9% to 16.4%). Implementing reminders alone improved care by 11.2% (IQR 6.5% to 19.6%) compared with usual care, while implementing reminders in addition to another intervention improved care by 4.0% only (IQR 3.0% to 6.0%) compared with the other intervention. The quality of evidence for these comparisons was rated as moderate according to the GRADE approach. Two reminder features were associated with larger effect sizes: providing space on the reminder for provider to enter a response (median 13.7% versus 4.3% for no response, P value = 0.01) and providing an explanation of the content or advice on the reminder (median 12.0% versus 4.2% for no explanation, P value = 0.02). Median improvement in processes of care also differed according to the behaviour the reminder targeted: for instance, reminders to vaccinate improved processes of care by 13.1% (IQR 12.2% to 20.7%) compared with other targeted behaviours. In the only study that had sufficient power to detect a clinically significant effect on outcomes of care, reminders were not associated with significant improvements. AUTHORS' CONCLUSIONS: There is moderate quality evidence that computer-generated reminders delivered on paper to healthcare professionals achieve moderate improvement in process of care. Two characteristics emerged as significant predictors of improvement: providing space on the reminder for a response from the clinician and providing an explanation of the reminder's content or advice. The heterogeneity of the reminder interventions included in this review also suggests that reminders can improve care in various settings under various conditions.
Resumo:
The propagation of an initially planar front is studied within the framework of the photosensitive Belousov-Zhabotinsky reaction modulated by a smooth spatial variation of the local front velocity in the direction perpendicular to front propagation. Under this modulation, the wave front develops several fingers corresponding to the local maxima of the modulation function. After a transient, the wave front achieves a stationary shape that does not necessarily coincide with the one externally imposed by the modulation. Theoretical predictions for the selection criteria of fingers and steady-state velocity are experimentally validated.
Resumo:
BACKGROUND: By reducing the amount of nicotine that reaches the brain when a person smokes a cigarette, nicotine vaccines may help people to stop smoking or to prevent recent quitters from relapsing. OBJECTIVES: The aims of this review are to assess the efficacy of nicotine vaccines for smoking cessation and for relapse prevention, and to assess the frequency and type of adverse events associated with the use of nicotine vaccines. SEARCH METHODS: We searched the Cochrane Tobacco Addiction Review Group specialised register for trials, using the term 'vaccine' in the title or abstract, or in a keyword (date of most recent search April 2012). To identify any other material including reviews and papers potentially relevant to the background or discussion sections, we also searched MEDLINE, EMBASE, and PsycINFO, combining terms for nicotine vaccines with terms for smoking and tobacco use, without design limits or limits for human subjects. We searched the Annual Meeting abstracts of the Society for Research on Nicotine and Tobacco up to 2012, using the search string 'vaccin'. We searched Google Scholar for 'nicotine vaccine'. We also searched company websites and Google for information related to specific vaccines. We searched clinicaltrials.gov in March 2012 for 'nicotine vaccine' and for the trade names of known vaccine candidates. SELECTION CRITERIA: We included randomized controlled trials of nicotine vaccines, at Phase II and Phase III trial stage and beyond, in adult smokers or recent ex-smokers. We included studies of nicotine vaccines used as part of smoking cessation or relapse prevention interventions. DATA COLLECTION AND ANALYSIS: We extracted data on the type of participants, the dose and duration of treatment, the outcome measures, the randomization procedure, concealment of allocation, blinding of participants and personnel, reporting of outcomes, and completeness of follow-up.Our primary outcome measure was a minimum of six months abstinence from smoking. We used the most rigorous definition of abstinence, and preferred cessation rates at 12 months and biochemically validated rates where available. We have used the risk ratio (RR) to summarize individual trial outcomes. We have not pooled the current group of included studies as they cover different vaccines and variable regimens. MAIN RESULTS: There are no nicotine vaccines currently licensed for public use, but there are a number in development. We found four trials which met our inclusion criteria, three comparing NicVAX to placebo and one comparing NIC002 (formerly NicQbeta) to placebo. All were smoking cessation trials conducted by pharmaceutical companies as part of the drug development process, and all trials were judged to be at high or unclear risk of bias in at least one domain. Overall, 2642 smokers participated in the included studies in this review. None of the four included studies detected a statistically significant difference in long-term cessation between participants receiving vaccine and those receiving placebo. The RR for 12 month cessation in active and placebo groups was 1.35 (95% Confidence Interval (CI) 0.82 to 2.22) in the trial of NIC002 and 1.74 (95% CI 0.73 to 4.18) in one NicVAX trial. Two Phase III NicVAX trials, for which full results were not available, reported similar quit rates of approximately 11% in both groups. In the two studies with full results available, post hoc analyses detected higher cessation rates in participants with higher levels of nicotine antibodies, but these findings are not readily generalisable. The two studies with full results showed nicotine vaccines to be well tolerated, with the majority of adverse events classified as mild or moderate. In the study of NIC002, participants receiving the vaccine were more likely to report mild to moderate adverse events, most commonly flu-like symptoms, whereas in the study of NicVAX there was no significant difference between the two arms. Information on adverse events was not available for the large Phase III trials of NicVAX.Vaccine candidates are likely to undergo significant changes before becoming available to the general public, and those included in this review may not be the first to reach market; this limits the external validity of the results reported in this review in terms of both effectiveness and tolerability. AUTHORS' CONCLUSIONS: There is currently no evidence that nicotine vaccines enhance long-term smoking cessation. Rates of serious adverse events recorded in the two trials with full data available were low, and the majority of adverse events reported were at mild to moderate levels. The evidence available suggests nicotine vaccines do not induce compensatory smoking or affect withdrawal symptoms. No nicotine vaccines are currently licensed for use in any country but a number are under development.Further trials of nicotine vaccines are needed, comparing vaccines with placebo for smoking cessation. Further trials are also needed to explore the potential of nicotine vaccines to prevent relapse. Results from past, current and future research should be reported in full. Adverse events and serious adverse events should continue to be carefully monitored and thoroughly reported.
Resumo:
BACKGROUND: Dietary fluoride supplements were first introduced to provide systemic fluoride in areas where water fluoridation is not available. Since 1990, the use of fluoride supplements in caries prevention has been re-evaluated in several countries. OBJECTIVES: To evaluate the efficacy of fluoride supplements for preventing dental caries in children. SEARCH METHODS: We searched the Cochrane Oral Health Group's Trials Register (to 12 October 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 3), MEDLINE via OVID (1950 to 12 October 2011), EMBASE via OVID (1980 to 12 October 2011), WHOLIS/PAHO/MEDCARIB/LILACS/BBO via BIREME (1982 to 12 October 2011), and Current Controlled Trials (to 12 October 2011). We handsearched reference lists of articles and contacted selected authors. SELECTION CRITERIA: We included randomised or quasi-randomised controlled trials comparing, with minimum follow-up of 2 years, fluoride supplements (tablets, drops, lozenges) with no fluoride supplement or with other preventive measures such as topical fluorides in children less than 16 years of age at the start. The main outcome was caries increment measured by the change in decayed, missing and filled tooth surfaces (DMFS). DATA COLLECTION AND ANALYSIS: Two review authors, independently and in duplicate, assessed the eligibility of studies for inclusion, and carried out risk of bias assessment and data extraction. In the event of disagreement, we sought consensus and consulted a third review author. We contacted trial authors for missing information. We used the prevented fraction (PF) as a metric for evaluating the efficacy of the intervention. The PF is defined as the mean caries increment in controls minus mean caries increment in the treated group divided by mean caries increment in controls. We conducted random-effects meta-analyses when data could be pooled. We assessed heterogeneity in the results of the studies by examining forest plots and by using formal tests for homogeneity. We recorded adverse effects (fluorosis) when the studies provided relevant data. MAIN RESULTS: We included 11 studies in the review involving 7196 children.In permanent teeth, when fluoride supplements were compared with no fluoride supplement (three studies), the use of fluoride supplements was associated with a 24% (95% confidence interval (CI) 16 to 33%) reduction in decayed, missing and filled surfaces (D(M)FS). The effect of fluoride supplements was unclear on deciduous or primary teeth. In one study, no caries-inhibiting effect was observed on deciduous teeth while in another study, the use of fluoride supplements was associated with a substantial reduction in caries increment.When fluoride supplements were compared with topical fluorides or with other preventive measures, there was no differential effect on permanent or deciduous teeth.The review found limited information on the adverse effects associated with the use of fluoride supplements. AUTHORS' CONCLUSIONS: This review suggests that the use of fluoride supplements is associated with a reduction in caries increment when compared with no fluoride supplement in permanent teeth. The effect of fluoride supplements was unclear on deciduous teeth. When compared with the administration of topical fluorides, no differential effect was observed. We rated 10 trials as being at unclear risk of bias and one at high risk of bias, and therefore the trials provide weak evidence about the efficacy of fluoride supplements.
Resumo:
The progression of liver fibrosis in chronic hepatitis C has long been considered to be independent from viral genotypes. However, recent studies suggest an association between Hepatitis C virus (HCV) genotype 3 and accelerated liver disease progression. We completed a systematic review and meta-analysis of studies evaluating the association between HCV genotypes and fibrosis progression. PubMed, Embase and ISI Web of Knowledge databases were searched for cohort, cross-sectional and case-control studies on treatment-naïve HCV-infected adults in which liver fibrosis progression rate (FPR) was assessed by the ratio of fibrosis stage in one single biopsy to the duration of infection (single-biopsy studies) or from the change in fibrosis stage between two biopsies (paired biopsies studies). A random effect model was used to derive FPR among different HCV genotypes. Eight single-biopsy studies (3182 patients, mean/median duration of infection ranging from 9 to 21 years) and eight paired biopsies studies (mean interval between biopsies 2-12 years) met the selection criteria. The odds ratio for the association of genotype 3 with accelerated fibrosis progression was 1.52 (95% CI 1.12-2.07, P = 0.007) in single-biopsy studies and 1.37 (95% CI 0.87-2.17, P = 0.17) in paired biopsy studies. In conclusion, viral genotype 3 was associated with faster fibrosis progression in single-biopsy studies. This observation may have important consequences on the clinical management of genotype 3-infected patients. The association was not significant in paired biopsies studies, although the latter may be limited by important indication bias, short observation time and small sample size.
Resumo:
Objective: Impaired blood flow of the gastric tube represents a major cause of anastomotic leakage after esophageal resection. In order to improve local vascularisation, preoperative embolization (PE) of the left gastric artery has recently been proposed. The aimof this study was to assess our initial experience of this novel approach with a particular focus on anastomotic leakage.Methods: A consecutive series of 102 patients (81 male, 21 female, median age 64 years) underwent resection (82 Ivor-Lewis procedures, 9 transhiatal resections, 11 triple incisions) for esophageal malignancies at our institution from 2000 to 2009. Since 2004, PE was used selectively in 19 patients 21 days prior to elective esophagectomy. Selection criteria were normal gastric vascular anatomy, no pre-existing vascular disease, i.e. atheromatosis of the celiac trunk or superior mesenteric artery, and resectability of the tumor. PE was performed under local anesthesia on a dedicated system in a standard fashion. Following percutaneous transfemoral visceral angiography to identify gastric vascular anatomy, embolization was performed either with 5-F or with coaxial 3-F catheters and fibered metal coils. We analyzed retrospectively patient's data, operative data, and outcome from a prospective database.Results: The overall anastomotic leakage rate was 18・6% (19/102 patients); cervical anastomosis had a leak rate of 25% compared to intrathoracic anastomosis leak rate of 18・2%. While 17 of 83 patients without PE developed anastomotic leakage (20・5%), there were only 2 of 19 patients after PE revealing an anastomotic leakage (10・5%). Otherwise, patients with PE had no more other complications. There was only one PE-related complication (i.e. partial splenic necrosis).Mean hospital stay was 25 days versus 27 days for patients with PE and without PE, respectively. The mortality rate was 7・8% (8/102 patients), whereby four deaths were related to anastomotic leakage (1 and 3 patients with PE and without PE, respectively).Conclusion: PE is an interesting novel approach to improve gastric blood flow in order to minimize anastomotic leakage. Its application is safe and technically easy. Our preliminary experience revealed a decrease of the anastomotic leakage rate of almost 50%.