Comparative evaluation of pyrethroid insecticide formulations against Triatoma infestans (Klug): residual efficacy on four substrates

We investigated the residual efficacy of four insecticide formulations used in Chagas disease vector control campaigns: cyfluthrin 12.5% suspension concentrace (SC), lambda-cyhalothrin 10% wettable powder (WP), deltamethrin 2.5% SC, and 2.5% WP on four types of circular blocks of wood, straw with mud, straw with mud painted with lime, and mud containing 5% of cement. Three concentrations of these insecticides were tested: the LC90 (previously determined on filter paper), the double of the LC90, and the recommended operational dose. For each bioassay test, 15 third-stage nymphs of Triatoma infestans (Klug) (Hemiptera: Reduviidae) were exposed for 120 h to each treatment at 24 h, 30, 60, 90, and 180 days post-spraying. Mortality rates, moulting history and behaviour were recorded at 24, 48, 72, and 120 h of exposure. Mortality rates were highest during the first 30 days post-spraying. Highest mortality rates (above 50%) were observed for deltamethrin 2.5% SC and lambda-cyhalothrin 10% WP on wood blocks up to three months post-spraying. Mud was the substrate on which treatments showed lowest persistence, with the other two substrates showing intermediate residual efficacy of all treatments. During the first 30 days WP formulations were not as effective as SC flowable formulations but, overall in the longer term, WP gave grater mortality rates of T. infestans nymphs exposed at up to six months post-spraying. Porous surfaces, especially mud, showed most variability presumably due to absorption of the insecticide. In contrast the less porous surfaces (i.e. wood and lime-coated mud) kept mortality rates high for longer post-treatment, irrespective of the insecticide concentration used.

Comparative population genomics in animals uncovers the determinants of genetic diversity.

Genetic diversity is the amount of variation observed between DNA sequences from distinct individuals of a given species. This pivotal concept of population genetics has implications for species health, domestication, management and conservation. Levels of genetic diversity seem to vary greatly in natural populations and species, but the determinants of this variation, and particularly the relative influences of species biology and ecology versus population history, are still largely mysterious. Here we show that the diversity of a species is predictable, and is determined in the first place by its ecological strategy. We investigated the genome-wide diversity of 76 non-model animal species by sequencing the transcriptome of two to ten individuals in each species. The distribution of genetic diversity between species revealed no detectable influence of geographic range or invasive status but was accurately predicted by key species traits related to parental investment: long-lived or low-fecundity species with brooding ability were genetically less diverse than short-lived or highly fecund ones. Our analysis demonstrates the influence of long-term life-history strategies on species response to short-term environmental perturbations, a result with immediate implications for conservation policies.

A comparative study of congenital toxoplasmosis between public and private hospitals from Uberlândia, MG, Brazil

The main purpose of the present study was to examine if there is difference in terms of incidence rates of congenital toxoplasmosis among populations assisted in public and private hospitals from Uberlândia, state of Minas Gerais, Brazil. A total of 805 serum samples from cord blood were collected, being 500 from public hospital and 305 from private hospital, and all patients answered a questionnaire about pregnancy and newborns. An indirect enzyme linked immunosorbent assay (ELISA) was performed to detect IgG antibodies to Toxoplasma gondii and the positive samples were retested to verify the presence of specific IgM and IgA antibodies in a capture ELISA. We found significant differences among data from both hospitals with respect to maternal age, origin city, gestational age, number of visits to physicians during pregnancy, type of delivery, and birth weight. Seroprevalence of IgG antibodies against T. gondii for patients from public and private hospitals was 57.6% and 41.9% respectively, and this difference was statistically significant (P < 0.0001). In addition, the frequency of congenital toxoplasmosis measured by the presence of IgM and/or IgA antibodies toward T. gondii was exclusively located in samples from public hospital (0.8%), and no positive sample was seen in private hospital (0%). Considering that almost all babies suffering from congenital toxoplasmosis, if undiagnosed and untreated, will develop visual or neurological impairments by adulthood, the results presented herein emphasized the importance to accomplish screening programs for toxoplasmosis during pregnancy, particularly in the public hospitals, due to the expressive rate of congenital disease showed in the patients attended at these centers.

Comparative analysis of ten assesment grids of quality criteria in qualitative research

The authors present 10 grids which are widely used in Health Sciences for the assessment of quality in research. They proceed through a comparative thematic analysis of these grids and show which points of view are preferred. They insist on the issues that differentiate these grids from each other and suggest the analysis of their differences by distinguishing the theoretical perspectives that underpin each one of these grids. Whilst the authors of the assessment grids rarely refer to the implicit theoretical backgrounds that guide their work, findings show that these grids convey varied epistemologies and research models. This gap renders the comparison of quality assessment in qualitative research a very difficult task, unless we shift our focus on the relationship between the grids, their theoretical backgrounds and their specific research subjects.

DIP-STR: Highly Sensitive Markers for the Analysis of Unbalanced Genomic Mixtures.

Samples containing highly unbalanced DNA mixtures from two individuals commonly occur both in forensic mixed stains and in peripheral blood DNA microchimerism induced by pregnancy or following organ transplant. Because of PCR amplification bias, the genetic identification of a DNA that contributes trace amounts to a mixed sample represents a tremendous challenge. This means that standard genetic markers, namely microsatellites, also referred as short tandem repeats (STR), and single-nucleotide polymorphism (SNP) have limited power in addressing common questions of forensic and medical genetics. To address this issue, we developed a molecular marker, named DIP-STR that relies on pairing deletion-insertion polymorphisms (DIP) with STR. This novel analytical approach allows for the unambiguous genotyping of a minor component in the presence of a major component, where DIP-STR genotypes of the minor were successfully procured at ratios up to 1:1,000. The compound nature of this marker generates a high level of polymorphism that is suitable for identity testing. Here, we demonstrate the power of the DIP-STR approach on an initial set of nine markers surveyed in a Swiss population. Finally, we discuss the limitations and potential applications of our new system including preliminary tests on clinical samples and estimates of their performance on simulated DNA mixtures.

Genomic characterization of a Brazilian TT Virus isolate closely related to SEN virus-F

SEN virus (SENV) is a circular, single stranded DNA virus that has been first characterized in the serum of a human immunodeficiency virus type 1 (HIV-1)-infected patient. Eight genotypes of SENV (A-H) have been identified and further recognized as variants of TT virus (TTV) in the family Circoviridae. Here we describe the first genomic characterization of a SENV isolate (5-A) from South America. Using 'universal' primers, able to amplify most, if not all, TTV/SENV genotypes, a segment of > 3 kb was amplified by polymerase chain reaction from the serum of an HIV-1 infected patient. The amplicon was cloned and a 3087-nucleotide sequence was determined, that showed a high (85%) homology with the sequence of the Italian isolate SENV-F. Proteins encoded by open reading frames (ORFs) 1 to 4 consisted of 758, 129, 276, and 267 amino acids, respectively. By phylogenetic analysis, isolate 5-A was classified into TTV genotype 19 (phylogenetic group 3), together with SENV-F and TTV isolate SAa-38.

A Comparative Study of Thermophilic Campylobacter Isolates of Clinical, Food and Pet Origin

Recent research, funded by safefood, has indicated a high occurrence of the food poisoning bacterium, Campylobacter in raw poultry, particularly chicken, with 49.9% of retail samples of raw chicken testing positive for the bacterium.

Evolution of vitellogenin genes: comparative analysis of the nucleotide sequences downstream of the transcription initiation site of four Xenopus laevis and one chicken gene.

Electron microscopic analysis of heteroduplexes between the most distantly related Xenopus vitellogenin genes (A genes X B genes) has revealed the distribution of homologous regions that have been preferentially conserved after the duplication events that gave rise to the multigene family in Xenopus laevis. DNA sequence analysis was limited to the region downstream of the transcription initiation site of the Xenopus genes A1, B1 and B2 and a comparison with the Xenopus A2 and the major chicken vitellogenin gene is presented. Within the coding regions of the first three exons, nucleotide substitutions resulting in amino acid changes accumulate at a rate similar to that observed in globin genes. This suggests that the duplication event which led to the formation of the A and B ancestral genes in Xenopus laevis occurred about 150 million years ago. Homologous exons of the A1-A2 and B1-B2 gene pairs, which formed about 30 million years ago, show a quite similar sequence divergence. In contrast, A1-A2 homologous introns seem to have evolved much faster than their B1-B2 counterparts.

A Comparative Study of Healthcare Professionals' Attitudes towards Clients with Dual Diagnosis.

The aim of this study was to explore the attitudes of Healthcare Professionals who work in the Substance Misuse Services compared to Healthcare Professionals who work in the Acute Mental Health Services towards clients with a dual diagnosis. A Likert type questionnaire was carried out between the two services, (n=45) from Substance Misuse and (n+54) from Mental Health Services of the multidiscipline teams. The results showed that there was a significant difference between the attitudes of the Healthcare Professionals in both Services. The Healthcare Professionals from the Substance Misuse Services displayed a more positive attitude towards clients with duel diagnosis, than professionals from the Acute Mental Health Services. These negative attitudes may affect the quality of care given to clients with a dual diagnosis. Healthcare Professionals need more knowledge and understanding about effective treatment for this client group. It is important that through collaboration from both services the care and treatment for clients with a dual diagnosis can be at optimal level.This resource was contributed by The National Documentation Centre on Drug Use.

Post-genomic update on a classical candidate gene for coronary artery disease: ESR1.

BACKGROUND: After age, sex is the most important risk factor for coronary artery disease (CAD). The mechanism through which women are protected from CAD is still largely unknown, but the observed sex difference suggests the involvement of the reproductive steroid hormone signaling system. Genetic association studies of the gene-encoding Estrogen Receptor α (ESR1) have shown conflicting results, although only a limited range of variation in the gene has been investigated. METHODS AND RESULTS: We exploited information made available by advanced new methods and resources in complex disease genetics to revisit the question of ESR1's role in risk of CAD. We performed a meta-analysis of 14 genome-wide association studies (CARDIoGRAM discovery analysis, N=≈87,000) to search for population-wide and sex-specific associations between CAD risk and common genetic variants throughout the coding, noncoding, and flanking regions of ESR1. In addition to samples from the MIGen (N=≈6000), WTCCC (N=≈7400), and Framingham (N=≈3700) studies, we extended this search to a larger number of common and uncommon variants by imputation into a panel of haplotypes constructed using data from the 1000 Genomes Project. Despite the widespread expression of ERα in vascular tissues, we found no evidence for involvement of common or low-frequency genetic variation throughout the ESR1 gene in modifying risk of CAD, either in the general population or as a function of sex. CONCLUSIONS: We suggest that future research on the genetic basis of sex-related differences in CAD risk should initially prioritize other genes in the reproductive steroid hormone biosynthesis system.

Cardiovascular disease, chronic kidney disease, and diabetes mortality burden of cardiometabolic risk factors from 1980 to 2010: a comparative risk assessment.

BACKGROUND: High blood pressure, blood glucose, serum cholesterol, and BMI are risk factors for cardiovascular diseases and some of these factors also increase the risk of chronic kidney disease and diabetes. We estimated mortality from cardiovascular diseases, chronic kidney disease, and diabetes that was attributable to these four cardiometabolic risk factors for all countries and regions from 1980 to 2010. METHODS: We used data for exposure to risk factors by country, age group, and sex from pooled analyses of population-based health surveys. We obtained relative risks for the effects of risk factors on cause-specific mortality from meta-analyses of large prospective studies. We calculated the population attributable fractions for each risk factor alone, and for the combination of all risk factors, accounting for multicausality and for mediation of the effects of BMI by the other three risks. We calculated attributable deaths by multiplying the cause-specific population attributable fractions by the number of disease-specific deaths. We obtained cause-specific mortality from the Global Burden of Diseases, Injuries, and Risk Factors 2010 Study. We propagated the uncertainties of all the inputs to the final estimates. FINDINGS: In 2010, high blood pressure was the leading risk factor for deaths due to cardiovascular diseases, chronic kidney disease, and diabetes in every region, causing more than 40% of worldwide deaths from these diseases; high BMI and glucose were each responsible for about 15% of deaths, and high cholesterol for more than 10%. After accounting for multicausality, 63% (10·8 million deaths, 95% CI 10·1-11·5) of deaths from these diseases in 2010 were attributable to the combined effect of these four metabolic risk factors, compared with 67% (7·1 million deaths, 6·6-7·6) in 1980. The mortality burden of high BMI and glucose nearly doubled from 1980 to 2010. At the country level, age-standardised death rates from these diseases attributable to the combined effects of these four risk factors surpassed 925 deaths per 100 000 for men in Belarus, Kazakhstan, and Mongolia, but were less than 130 deaths per 100 000 for women and less than 200 for men in some high-income countries including Australia, Canada, France, Japan, the Netherlands, Singapore, South Korea, and Spain. INTERPRETATION: The salient features of the cardiometabolic disease and risk factor epidemic at the beginning of the 21st century are high blood pressure and an increasing effect of obesity and diabetes. The mortality burden of cardiometabolic risk factors has shifted from high-income to low-income and middle-income countries. Lowering cardiometabolic risks through dietary, behavioural, and pharmacological interventions should be a part of the global response to non-communicable diseases. FUNDING: UK Medical Research Council, US National Institutes of Health.

Comparative effectiveness research across two spine registries.

BACKGROUND: Comparative effectiveness research in spine surgery is still a rarity. In this study, pain alleviation and quality of life (QoL) improvement after lumbar total disc arthroplasty (TDA) and anterior lumbar interbody fusion (ALIF) were anonymously compared by surgeon and implant. METHODS: A total of 534 monosegmental TDAs from the SWISSspine registry were analyzed. Mean age was 42 years (19-65 years), 59% were females. Fifty cases with ALIF were documented in the international Spine Tango registry and used as concurrent comparator group for the pain analysis. Mean age was 46 years (21-69 years), 78% were females. The average follow-up time in both samples was 1 year. Comparison of back/leg pain alleviation and QoL improvement was performed. Unadjusted and adjusted probabilities for achievement of minimum clinically relevant improvements of 18 VAS points or 0.25 EQ-5D points were calculated for each surgeon. RESULTS: Mean preoperative back pain decreased from 69 to 30 points at 1 year (ØΔ 39pts) after TDA, and from 66 to 27 points after ALIF (ØΔ 39pts). Mean preoperative QoL improved from 0.34 to 0.74 points at 1 year (ØΔ 0.40pts). There were surgeons with better patient selection, indicated by lower adjusted probabilities reflecting worsening of outcomes if they had treated an average patient sample. ALIF had similar pain alleviation than TDA. CONCLUSIONS: Pain alleviation after TDA and ALIF was similar. Differences in surgeon's patient selection based on pain and QoL were revealed. Some surgeons seem to miss the full therapeutic potential of TDA by selecting patients with lower symptom severity.