Gene silencing by RNAi via oral delivery of dsRNA by bacteria in the South American tomato pinworm, Tuta absoluta.

BACKGROUND: RNA interference (RNAi) has been evaluated in several insect pests as a novel strategy to be included in integrated pest management. Lepidopterans are recognized to be recalcitrant to gene silencing by RNAi. As such, double-stranded RNA (dsRNA) delivery needs to be adjusted to assure its stability until it reaches the target gene transcript for silencing. Gene silencing by RNAi offers the potential to be used in the control of Tuta absoluta (Meyrick), one of the main insect pests of tomato (Solanum lycopersicum) worldwide. Here, we tested the delivery of dsRNA expressed in Escherichia coli HT115(DE3) and supplied to larvae in an artificial diet by screening target genes for silencing. We tested six target genes: juvenile hormone inducible protein (JHP); juvenile hormone epoxide hydrolase protein (JHEH); ecdysteroid 25-hydroxylase (PHM); chitin synthase A (CHI); carboxylesterase (COE); and arginine kinase (AK). RESULTS: Based on larval mortality, the duration of the larval stage in days, pupal weight, and the accumulation of the target gene transcript, we demonstrated the efficacy of bacterial dsRNA delivery for the functional effects on larval development. Providing dsRNA targeted to JHP, CHI, COE and AK by bacteria led to a significant decrease in transcript accumulation and an increase in larval mortality. CONCLUSION: Bacteria expressing dsRNA targeting essential T. absoluta genes supplied in artificial diet are efficient to screen RNAi target-genes. The oral delivery of dsRNA by bacteria is a novel potential alternative for the control of T. absoluta based on RNAi. © 2019 Society of Chemical Industry.

Health Economic Evaluations of Cancer in Brazil: A Systematic Review.

Background: A large number of health economic evaluation (HEE) studies have been published in developed countries. However, Brazilian HEE literature in oncology has not been studied. OBJECTIVE: To investigate whether the scientific literature has provided a set of HEE in oncology capable of supporting decision making in the Brazilian context. Methods: A systematic review was conducted to identify and characterize studies in this field. We searched multiple databases selecting partial and full HEE studies in oncology (1998-2013). Results: Fifty-five articles were reviewed, of these, 33 (60%) were full health economic evaluations. Type of cancers most frequently studied were: breast (38.2%), cervical (14.6%), lung (10.9%) and colorectal (9.1%). Procedures (47.3%) were the technologies most frequently evaluated. In terms of the intended purposes of the technologies, most (63.6%) were treatments. The majority of the incremental cost-effectiveness ratios (ICERs) reported have been below the cost-effectiveness threshold suggested by the World Health Organization (WHO). Conclusions: There has been an increase in the number of HEEs related to cancer in Brazil. These studies may support decision-making processes regarding the coverage of and reimbursement of healthcare technologies for cancer treatment in Brazil.

Systematic Review of Health Economic Evaluation Studies Developed in Brazil from 1980 to 2013.

BACKGROUND: Brazil has sought to use economic evaluation to support healthcare decision-making processes. While a number of health economic evaluations (HEEs) have been conducted, no study has systematically reviewed the quality of Brazilian HEE. The objective of this systematic review was to provide an overview regarding the state of HEE research and to evaluate the number, characteristics, and quality of reporting of published HEE studies conducted in a Brazilian setting. METHODS: We systematically searched electronic databases (MEDLINE, EMBASE, Latin American, and Caribbean Literature on Health Sciences Database, Scientific Electronic Library Online, NHS Economic Evaluation Database, health technology assessment Database, Bireme, and Biblioteca Virtual em Saúde Economia da Saúde); citation indexes (SCOPUS, Web of Science), and Sistema de Informação da Rede Brasileira de Avaliação de Tecnologia em Saúde. Partial and full HEEs published between 1980 and 2013 that referred to a Brazilian setting were considered for inclusion. RESULTS: In total, 535 studies were included in the review, 36.8% of these were considered to be full HEE. The category of healthcare technologies more frequently assessed were procedures (34.8%) and drugs (28.8%) which main objective was treatment (72.1%). Forty-four percent of the studies reported their funding source and 36% reported a conflict of interest. Overall, the full HEE quality of reporting was satisfactory. But some items were generally poorly reported and significant improvement is required: (1) methods used to estimate healthcare resource use quantities and unit costs, (2) methods used to estimate utility values, (3) sources of funding, and (4) conflicts of interest. CONCLUSION: A steady number of HEE have been published in Brazil since 1980. To improve their contribution to inform national healthcare policy efforts need to be made to enhance the quality of reporting of HEEs and promote improvements in the way HEEs are designed, implemented (i.e., using sound methods for HEEs) and reported.

Systematic Review of Health Economic Evaluations of Diagnostic Tests in Brazil: How accurate are the results?

The aim of this study is to identify and characterize the health economic evaluations (HEEs) of diagnostic tests conducted in Brazil, in terms of their adherence to international guidelines for reporting economic studies and specific questions in test accuracy reports. We systematically searched multiple databases, selecting partial and full HEEs of diagnostic tests, published between 1980 and 2013. Two independent reviewers screened articles for relevance and extracted the data. We performed a qualitative narrative synthesis. Forty-three articles were reviewed. The most frequently studied diagnostic tests were laboratory tests (37.2%) and imaging tests (32.6%). Most were non-invasive tests (51.2%) and were performed in the adult population (48.8%). The intended purposes of the technologies evaluated were mostly diagnostic (69.8%), but diagnosis and treatment and screening, diagnosis, and treatment accounted for 25.6% and 4.7%, respectively. Of the reviewed studies, 12.5% described the methods used to estimate the quantities of resources, 33.3% reported the discount rate applied, and 29.2% listed the type of sensitivity analysis performed. Among the 12 cost-effectiveness analyses, only two studies (17%) referred to the application of formal methods to check the quality of the accuracy studies that provided support for the economic model. The existing Brazilian literature on the HEEs of diagnostic tests exhibited reasonably good performance. However, the following points still require improvement: 1) the methods used to estimate resource quantities and unit costs, 2) the discount rate, 3) descriptions of sensitivity analysis methods, 4) reporting of conflicts of interest, 5) evaluations of the quality of the accuracy studies considered in the cost-effectiveness models, and 6) the incorporation of accuracy measures into sensitivity analyses.

Systematic Review of Health Economic Evaluations of Diagnostic Tests in Brazil: How accurate are the results?

The aim of this study is to identify and characterize the health economic evaluations (HEEs) of diagnostic tests conducted in Brazil, in terms of their adherence to international guidelines for reporting economic studies and specific questions in test accuracy reports. We systematically searched multiple databases, selecting partial and full HEEs of diagnostic tests, published between 1980 and 2013. Two independent reviewers screened articles for relevance and extracted the data. We performed a qualitative narrative synthesis. Forty-three articles were reviewed. The most frequently studied diagnostic tests were laboratory tests (37.2%) and imaging tests (32.6%). Most were non-invasive tests (51.2%) and were performed in the adult population (48.8%). The intended purposes of the technologies evaluated were mostly diagnostic (69.8%), but diagnosis and treatment and screening, diagnosis, and treatment accounted for 25.6% and 4.7%, respectively. Of the reviewed studies, 12.5% described the methods used to estimate the quantities of resources, 33.3% reported the discount rate applied, and 29.2% listed the type of sensitivity analysis performed. Among the 12 cost-effectiveness analyses, only two studies (17%) referred to the application of formal methods to check the quality of the accuracy studies that provided support for the economic model. The existing Brazilian literature on the HEEs of diagnostic tests exhibited reasonably good performance. However, the following points still require improvement: 1) the methods used to estimate resource quantities and unit costs, 2) the discount rate, 3) descriptions of sensitivity analysis methods, 4) reporting of conflicts of interest, 5) evaluations of the quality of the accuracy studies considered in the cost-effectiveness models, and 6) the incorporation of accuracy measures into sensitivity analyses.

A systematic review of health economic evaluations of vaccines in Brazil.

BACKGROUND: In Brazil, since 2005, the Ministry of Health requires Health Economic Evaluation (HEE) of vaccines for introduction into the National Immunization Program. OBJECTIVES: To describe and analyze the full HEE on vaccines conducted in Brazil from 1980 to 2013. METHODS: Systematic review of the literature. We searched multiple databases. Two researchers independently selected the studies and extracted the data. The methodological quality of individual studies was evaluated using CHEERS items. RESULTS: Twenty studies were reviewed. The most evaluated vaccines were pneumococcal (25%) and HPV (15%). The most used types of HEE were cost-effectiveness analysis (45%) and cost-utility analysis (20%). The research question and compared strategies were stated in all 20 studies and the target population was clear in 95%. Nevertheless, many studies did not inform the perspective of analysis or data sources. CONCLUSIONS: HEE of vaccines in Brazil has increased since 2008. However, the studies still have methodological deficiencies.

Many Miles to Go: A Systematic Review of the State of Cost-Utility Analyses in Brazil.

BACKGROUND: Little is known about the quality and quantity of cost-utility analyses (CUAs) in Brazil. OBJECTIVE: The objective of this study was to provide a systematic review of published CUAs of healthcare technologies in Brazil. METHODS: We performed a systematic review of economic evaluations studies published in MEDLINE, EMBASE, LILACS (Latin American and Caribbean Health Sciences Literature), SciELO (Scientific Electronic Library Online), NHS EED (National Health Service Economic Evaluation Database), HTA (Health Technology Assessment) Database, Web of Science, Scopus, Bireme (Biblioteca Regional de Medicina), BVS ECOS (Health Economics database of the Brazilian Virtual Library of Health), and SISREBRATS (Sistema de Informação da Rede Brasileira de Avaliação de Tecnologias em Saúde [Brazilian Network for the Evaluation of Health Technologies]) from 1980 to 2013. Articles were included if they were CUAs according to the classification devised by Drummond et al. Two independent reviewers screened articles for relevance and carried out data extraction. Disagreements were resolved through discussion or through consultation with a third reviewer. We performed a qualitative narrative synthesis. RESULTS: Of the 535 health economic evaluations (HEEs) relating to Brazil, only 40 were CUAs and therefore included in the analysis. Most studies adhered to methodological guidelines for quality of reporting and 77.5% used quality-adjusted life-years (QALYs) as the health outcome. Of these studies, 51.6% did not report the population used to elicit preferences for outcomes and 45.2% used a specific population such as expert opinion. The preference elicitation method was not reported in 58.1% of these studies. The majority (80.6%) of studies did not report the instrument used to derive health state valuations and no publication reported whether tariffs (or preference weights) were national or international. No study mentioned the methodology used to estimate QALYs. CONCLUSIONS: Many published Brazilian cost-utility studies adhere to key recommended general methods for HEE; however, the use of QALY calculations is far from being the current international standard. Development of health preferences research can contribute to quality improvement of health technology assessment reports in Brazil.

Economic evaluations in gastroenterology in Brazil: A systematic review.

AIM: To systematically review economic evaluations in gastroenterology, relating to Brazil, published between 1980 and 2013. METHODS: We selected full and partial economic evaluations from among those retrieved by searching the following databases: MEDLINE (PubMed); Excerpta Medica; the Latin American and Caribbean Health Sciences Literature database; the Scientific Electronic Library Online; the database of the Centre for Reviews and Dissemination; the National Health Service (NHS) Economic Evaluation Database; the NHS Health Technology Assessment database; the Health Economics database of the Brazilian Virtual Library of Health; Scopus; Web of Science; and the Brazilian Network for the Evaluation of Health Technologies. Two researchers, working independently, selected the studies and extracted the data. RESULTS: We identified 535 health economic evaluations relating to Brazil and published in the 1980-2013 period. Of those 535 articles, only 40 dealt with gastroenterology. Full and partial economic evaluations respectively accounted for 23 (57.5%) and 17 (42.5%) of the 40 studies included. Among the 23 full economic evaluations, there were 11 cost-utility analyses, seven cost-effectiveness analyses, four cost-consequence analyses, and one cost-minimization analysis. Of the 40 studies, 25 (62.5%) evaluated medications; 7 (17.5%) evaluated procedures; and 3 (7.5%) evaluated equipment. Most (55%) of the studies were related to viral hepatitis, and most (63.4%) were published after 2010. Other topics included gastrointestinal cancer, liver transplantation, digestive diseases and hernias. Over the 33-year period examined, the number of such economic evaluations relating to Brazil, especially of those evaluating medications for the treatment of hepatitis, increased considerably. CONCLUSION: Further studies are needed in order to ensure that expenditures on health care in Brazil are made as fairly and efficiently as possible.

Experimental power considerations--justifying replication for animal care and use committees.

A common practice in poultry science is to compare new treatments with a control or between treatments tested in planned experiments. The overall F-test from an ANOVA of the data allows the researcher to reject or not reject the null hypothesis. However, the correct conclusion from such analysis depends on sufficient replicates being included in the experiment. On the other hand, restrictions are imposed to reduce the number of birds used in experiments for welfare reasons and to save scarce resources. We review the basic concepts needed to determine the number of replicates before conducting an experiment. We use these concepts to assess the results of several real experiments and to show what might be done in future experiments. We describe how to do the computations in R software.