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1.
Evid Policy ; 17(4): 689-707, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35586821

RESUMO

Background: There is growing interest in and recognition of the need to use scientific evidence to inform policymaking. However, many of the existing studies on the use of research evidence (URE) have been largely qualitative, and the majority of existing quantitative measures are underdeveloped or were tested in regional or context-dependent settings. We are unaware of any quantitative measures of URE with national policymakers in the US. Aims and objectives: Explore how to measure URE quantitatively by validating a measure of congressional staff's attitudes and behaviors regarding URE, the Legislative Use of Research Survey (LURS), and by discussing the lessons learned through administering the survey. Methods: A 68-item survey was administered to 80 congressional staff to measure their reported research use, value of research, interactions with researchers, general information sources, and research information sources. Confirmatory factor analyses were conducted on each of these five scales. We then trimmed the number of items, based on a combination of poor factor loadings and theoretical rationale, and ran the analyses on the trimmed subscales. Findings: We substantially improved our model fits for each scale over the original models and all items had acceptable factor loadings with our trimmed 35-item survey. We also describe the unique set of challenges and lessons learned from surveying congressional staff. Discussion and conclusions: This work contributes to the transdisciplinary field of URE by offering a tool for studying the mechanisms that can bridge research and policy and shedding light into best practices for measuring URE with national policymakers in the US.

2.
J Dairy Sci ; 100(9): 7446-7454, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28711261

RESUMO

Endemic diseases can be counted among the most serious sources of losses for livestock production. In dairy farms in particular, one of the most common diseases is Johne's disease, caused by Mycobacterium avium ssp. paratuberculosis (MAP). Infection with MAP causes direct costs because it affects milk production, but it has also been suspected to increase the risk of clinical mastitis (CM) among infected animals. This might contribute to further costs for farmers. We asked whether MAP infection represents a risk factor for CM and, in particular, whether CM occurrences were more common in MAP-infected animals. Our results, obtained by survival analysis, suggest that MAP-infected cows had an increased probability of experiencing CM during lactation. These results highlight the need to account for the interplay of infectious diseases and other health conditions in economic and epidemiological modeling. In this case, accounting for MAP-infected cows having an increased CM occurrence might have nonnegligible effects on the estimated benefit of MAP control.


Assuntos
Lactação , Mastite Bovina/microbiologia , Mycobacterium avium subsp. paratuberculosis , Paratuberculose/microbiologia , Animais , Bovinos , Feminino
3.
N Z Vet J ; 65(1): 51-55, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27691906

RESUMO

CASE HISTORY: A group of 545 pregnant rising 2-year-old Coopdale ewes on a Southland sheep farm were grazed over winter on a fodder beet (Beta vulgaris) crop. Subsequently, 45 out of approximately 750 lambs were born with a variety of skeletal deformities, including shortened limbs, varus and valgus angular limb deformities, palmar grade stance and cranial bowing of the carpus. Analysis of the crop showed the fodder beet contained a low percentage of phosphorus. In addition, 60 out of 460 rising 2-year-old ewes that had been grazed on the fodder beet crop as 1-year-olds had incisor abnormalities and malocclusion. PATHOLOGICAL FINDINGS: Two affected lambs (1-day-old and 3-days-old) with representative clinical signs examined postmortem were found to have markedly enlarged costochondral junctions, and noticeably enlarged long bone metaphyses. In addition, one lamb had a dense band of metaphyseal sclerosis beneath the physes of all long bones examined. Histopathological findings included small islands and columns of chondrocytes and eosinophilic cartilage matrix present in the metaphysis. Metaphyseal trabeculae were disorganised and often lined by accumulations of pale pink osteoid; similar pale pink osteoid was also present in the cortices. Unerupted molar teeth in the affected lambs lacked a layer of enamel, and the dentine was irregular with globular basophilia. DIAGNOSIS: The gross and histopathological lesions were consistent with a diagnosis of rickets. CLINICAL RELEVANCE: Nutritional congenital rickets has not been previously diagnosed in sheep, but is a recognised disease of human infants with vitamin D deficient mothers. The rickets in affected lambs was most likely associated with phosphorus deficiency as a result of the pregnant ewes grazing fodder beet during gestation. While vitamin D deficiency was not definitively ruled out in these cases, practitioners are alerted to the possible effects of feeding phosphorus-deficient fodder beet to ewes for long periods during gestation and to 1-year-old sheep during important growth periods.


Assuntos
Raquitismo/veterinária , Doenças dos Ovinos/congênito , Anormalidades Múltiplas/patologia , Anormalidades Múltiplas/veterinária , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Feminino , Anormalidades Musculoesqueléticas/patologia , Anormalidades Musculoesqueléticas/veterinária , Raquitismo/congênito , Ovinos , Doenças dos Ovinos/patologia
4.
Eur J Clin Pharmacol ; 72(9): 1099-104, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27353638

RESUMO

PURPOSE: Valproic acid (VPA) has an extensive interindividual pharmacokinetic variability. Published data regarding the impact of gender, age, and CYP2C9/2C19 genetics on VPA variability are conflicting, and the purpose of present study is to clarify the effect of these factors on dose-adjusted steady-state serum VPA concentration (C:D ratio) in a large, naturalistic patient material. METHODS: In patients who had been subjected to cytochrome P450 (CYP) genotyping and therapeutic drug monitoring of VPA, information about serum concentrations, dose, gender, age, and CYP2C9/2C19 genotypes was retrospectively collected from a routine TDM database during the period 2008-2012. The effects of age, gender, and CYP2C9/CYP2C19 genotypes on C:D ratios of VPA were investigated by multivariate analyses (mixed model) including sampling time as covariate. RESULTS: In total, 857 serum concentrations from 252 patients were included. A significant gender effect was observed with a 1.3-fold higher estimated C:D ratio in females than in males, i.e., geometric means 0.34 vs. 0.27 µM/mg/day, respectively (p < 0.001). A similar and significant difference in estimated geometric means was found between patients >65 vs. ≤65 years, i.e., 0.36 vs. 0.26 µM/mg/day (p < 0.001), respectively. Finally, no association between the various CYP2C9/2C19 variant genotypes and C:D ratio of VPA was observed (p > 0.1). CONCLUSION: The present study shows that age and gender significantly influence VPA serum concentration. In order to obtain similar drug exposure, our findings suggest that older female patients would generally require 30-50 % lower dosing of VPA compared to younger males. Moreover, we conclude that CYP2C9/2C19 genotype is not relevant for variability in VPA exposure.


Assuntos
Anticonvulsivantes/sangue , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP2C9/genética , Ácido Valproico/sangue , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Anticonvulsivantes/farmacocinética , Monitoramento de Medicamentos , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Ácido Valproico/farmacocinética , Adulto Jovem
5.
Child Care Health Dev ; 41(6): 873-81, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26119480

RESUMO

BACKGROUND: There is minimal literature on how parents experiencing intergenerational poverty view their role as parents and the value they place on children's play. The objective of this study was to examine how these parents view their parenting role and their beliefs about children's play. METHODS: Thirteen mothers of preschool-aged children who experienced intergenerational poverty were recruited to the study. Semi-structured interviews were conducted and were analysed using interpretive phenomenological analysis. RESULTS: Parents described their role as guiding their children to become 'good' people, to teach them skills and provide a routine within the home. There were two disconnections in the data including the view that whilst parenting was hard and lonely, it was also a private matter and participants preferred not to seek support. A second disconnection was in terms of their beliefs about play. Parents believed that whilst play was valuable to their child's development, it was not their role to play with children. However, if parents did play with their child, they noticed positive changes in their child's behaviour. CONCLUSION: The views of parents who experienced intergenerational poverty were similar to other reported findings in parenting studies. However, the current sample differed on not seeking help for support as well as not seeing their role as playing with their children, even though occasions of joining their child in play were associated with a positive change in their relationship with their child. This has implications for communicating about parenting issues with parents who have experienced intergenerational poverty.


Assuntos
Atitude Frente a Saúde , Desenvolvimento Infantil , Poder Familiar/psicologia , Pais/psicologia , Jogos e Brinquedos/psicologia , Adulto , Pré-Escolar , Feminino , Humanos , Relações Pais-Filho , Pobreza , Pesquisa Qualitativa , Classe Social , Televisão , Vitória
6.
Emerg Radiol ; 22(4): 453-5, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25792463

RESUMO

Paediatric stroke is a major cause of morbidity and death in children. There is often a delay in making the diagnosis because common differential diagnoses such as migraine and seizures need to be considered and quick access to imaging is difficult. Early recognition is increasingly important for early treatment and to improve outcomes. We present the case of a 4-year-old boy who presented to the Emergency Department with acute hemiparesis. To target the provisional diagnosis of an acute ischaemic stroke, we requested magnetic resonance imaging (MRI) limited to two sequences only: diffusion weighted imaging (DWI) and susceptibility weighted imaging (SWI). We were able to confirm the diagnosis of acute ischaemic stroke within 90 min of presentation to hospital.


Assuntos
Isquemia Encefálica/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Acidente Vascular Cerebral/diagnóstico , Pré-Escolar , Serviço Hospitalar de Emergência , Humanos , Masculino
7.
Chem Res Toxicol ; 27(7): 1092-103, 2014 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-24857813

RESUMO

The metabolic fate of a compound is determined by numerous factors including its chemical structure. Although the metabolic options for a variety of functional groups are well understood and can often provide a rationale for the comparison of toxicity based on structural analogy, at times quite minor structural variations may have major consequences for metabolic outcomes and toxicity. In this perspective, the effects of structural variations on metabolic outcomes is detailed for a group of related hydroxy- and alkoxy-substituted allyl- and propenylbenzenes. These classes of compounds are naturally occurring constituents of a variety of botanical-based food items. The classes vary from one another by the presence or absence of alkylation of their para-hydroxyl substituents and/or the position of the double bond in the alkyl side chain. We provide an overview of how these subtle structural variations alter the metabolism of these important food-borne compounds, ultimately influencing their toxicity, particularly their DNA reactivity and carcinogenic potential. The data reveal that detailed knowledge of the consequences of subtle structural variations for metabolism is essential for adequate comparison of structurally related chemicals. Taken together, it is concluded that predictions in toxicological risk assessment should not be performed on the basis of structural analogy only but should include an analogy of metabolic pathways across compounds and species.


Assuntos
Derivados de Benzeno , Carcinógenos , Animais , Derivados de Benzeno/química , Derivados de Benzeno/farmacocinética , Derivados de Benzeno/toxicidade , Biotransformação , Carcinógenos/química , Carcinógenos/farmacocinética , Carcinógenos/toxicidade , Humanos
8.
Heliyon ; 10(3): e25789, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38352775

RESUMO

Tickborne diseases (TBDs) are increasingly prevalent in Illinois and the Upper Midwest region. People who work in occupations that require time outdoors in agricultural or natural settings, such as some Extension workers, are at risk of tick bites and TBDs. Additionally, Extension workers are often a primary source of information about ticks and TBDs in rural communities. However, there is limited information on the level of awareness about ticks and TBDs in the Extension community. The goals of this study were to sequentially i) determine the baseline awareness of Extension workers in Illinois about ticks and TBDs using a knowledge, attitudes, and practices (KAP) survey tool, ii) provide comprehensive training on ticks and TBDs to this demographic, and iii) measure the uptake of knowledge after the training intervention through a post-training survey. The study period was from June 2022 until May 2023. We received 233 pre-training and 93 paired post-training survey responses. Most survey respondents were Extension volunteers, identified as women, and were over 50 years old. Knowledge about ticks and TBDs varied. We identified several gaps in their current tick awareness, most importantly, in tick prevention measures, tick identification, and TBDs in general. TBD knowledge, attitude, and practice scores all significantly improved after training (p < 0.001), with a mean difference of 10.47, 1.49, and 2.64 points, respectively. Additionally, both Extension professionals (79.2 %) and Extension volunteers (66.7 %) were more likely to feel confident in engaging with their stakeholders on ticks and TBDs after participating in training. Poisson models revealed that higher attitude and practice scores and greater self-reported knowledge were the factors most significantly associated with higher TBD knowledge. We found that greater concern for ticks and TBD (attitudes) and adherence to science-based prevention and management methods (practices) were also associated with higher knowledge scores. To our knowledge, this is the first study in Illinois to capture Extension workers' awareness of ticks and TBDs. The results highlight Extension workers' interest in filling knowledge gaps through learning, and the importance of training Extension workers to disseminate reliable and updated information on ticks and TBDs to their constituents, a critical step in preventing TBDs.

9.
Br J Dermatol ; 168(4): 864-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23106574

RESUMO

BACKGROUND: Phenotypically diverse autoimmune conditions share common genetic susceptibility loci and underlying molecular pathways. OBJECTIVES: By systematically searching for single nucleotide polymorphisms (SNPs) associated with another autoimmune disease, rheumatoid arthritis (RA), we aimed to elucidate novel genetic markers of psoriasis. METHODS: We investigated 18 SNPs, previously confirmed as being associated with RA, in a U.K. cohort of 623 patients with early-onset psoriasis (presenting before age 40 years), comparing them with 2662 control subjects. RESULTS: Our findings confirm the association of early-onset psoriasis with REL (rs13031237, P=0·0027). The minor allele of REL had opposing effects upon susceptibility to disease in patients with psoriasis and RA. CONCLUSION: Similar exploration of additional autoimmune loci and fine mapping of such regions may provide further insight into the genetics and molecular pathophysiology of psoriasis.


Assuntos
Artrite Reumatoide/genética , Genes rel/genética , Polimorfismo de Nucleotídeo Único/genética , Psoríase/genética , Adulto , Marcadores Genéticos/genética , Predisposição Genética para Doença/genética , Genótipo , Humanos , Fatores de Risco
10.
Nat Genet ; 17(4): 491-4, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9398858

RESUMO

Individuals with primary trimethylaminuria exhibit a body odour reminiscent of rotting fish, due to excessive excretion of trimethylamine (TMA; refs 1-3). The disorder, colloquially known as fish-odour syndrome, is inherited recessively as a defect in hepatic N-oxidation of dietary-derived TMA and cannot be considered benign, as sufferers may display a variety of psychosocial reactions, ranging from social isolation of clinical depression and attempted suicide. TMA oxidation is catalyzed by flavin-containing mono-oxygenase (FMO; refs 7,8), and tissue localization and functional studies have established FMO3 as the form most likely to be defective in fish-odour syndrome. Direct sequencing of the coding exons of FMO3 amplified from a patient with fish-odour syndrome identified two missense mutations. Although one of these represented a common polymorphism, the other, a C-->T transition in exon 4, was found only in an affected pedigree, in which it segregated with the disorder. The latter mutation predicts a proline-->leucine substitution at residue 153 and abolishes FMO3 catalytic activity. Our results indicate that defects in FMO3 underlie fish-odour syndrome and that the Pro 153-->Leu 153 mutation described here is a cause of this distressing condition.


Assuntos
Erros Inatos do Metabolismo/enzimologia , Metilaminas/urina , Mutação , Odorantes , Oxigenases/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Humanos , Erros Inatos do Metabolismo/genética , Dados de Sequência Molecular , Oxirredução , Linhagem , Síndrome
11.
Sci Rep ; 13(1): 1428, 2023 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-36697468

RESUMO

The ongoing COVID-19 pandemic is among the worst in recent history, resulting in excess of 520,000,000 cases and 6,200,000 deaths worldwide. The United States (U.S.) has recently surpassed 1,000,000 deaths. Individuals who are elderly and/or immunocompromised are the most susceptible to serious sequelae. Rising sentiment often implicates younger, less-vulnerable populations as primary introducers of COVID-19 to communities, particularly around colleges and universities. Adjusting for more than 32 key socio-demographic, economic, and epidemiologic variables, we (1) implemented regressions to determine the overall community-level, age-adjusted COVID-19 case and mortality rate within each American county, and (2) performed a subgroup analysis among a sample of U.S. colleges and universities to identify any significant preliminary mitigation measures implemented during the fall 2020 semester. From January 1, 2020 through March 31, 2021, a total of 22,385,335 cases and 374,130 deaths were reported to the CDC. Overall, counties with increasing numbers of university enrollment showed significantly lower case rates and marginal decreases in mortality rates. County-level population demographics, and not university level mitigation measures, were the most significant predictor of adjusted COVID-19 case rates. Contrary to common sentiment, our findings demonstrate that counties with high university enrollments may be more adherent to public safety measures and vaccinations, likely contributing to safer communities.


Assuntos
COVID-19 , Humanos , Estados Unidos/epidemiologia , Idoso , COVID-19/epidemiologia , Universidades , Pandemias , Estudos Longitudinais , Progressão da Doença
12.
Osteoarthritis Cartilage ; 20(11): 1309-15, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22868052

RESUMO

OBJECTIVE: To evaluate the hypothesis that a mechanical stimulus (30-min walk) will produce a change in serum concentrations of cartilage oligomeric matrix protein (COMP) that is associated with cartilage thickness changes on magnetic resonance imaging (MRI). METHODS: Serum COMP concentrations were measured by enzyme-linked immunosorbent assay in 17 patients (11 females, age: 59.0±9.2 years) with medial compartment knee osteoarthritis (OA) at study entry immediately before, immediately after, 3.5 h, and 5.5 h after a 30-min walking activity. Cartilage thickness changes in the medial femur and medial tibia were determined from MR images taken at study entry and at 5-year follow-up. Relationships between changes in cartilage thickness and COMP levels, with post-activity concentrations expressed as a percentage of pre-activity levels, were assessed by the calculation of Pearson correlation coefficients and by multiple linear regression analysis, with adjustments for age, sex, and body mass index (BMI). RESULTS: Changes in COMP levels 3.5 h and 5.5 h post-activity were correlated with changes in cartilage thickness in the medial femur and tibia at the 5-year follow-up. The results were strengthened after analyses were adjusted for age, sex, and BMI. Neither baseline pre-activity COMP levels nor changes in COMP levels immediately post-activity were correlated with cartilage thickness changes. CONCLUSIONS: The results of this study support the hypothesis that a change in COMP concentration induced by a mechanical stimulus is associated with cartilage thinning at 5 years. Mechanically-induced changes in mechano-sensitive biomarkers should be further explored in the context of stimulus-response models to improve the ability to assess OA progression.


Assuntos
Cartilagem Articular/patologia , Proteínas da Matriz Extracelular/sangue , Glicoproteínas/sangue , Mecanotransdução Celular/fisiologia , Osteoartrite do Joelho/patologia , Caminhada/fisiologia , Fenômenos Biomecânicos , Índice de Massa Corporal , Proteína de Matriz Oligomérica de Cartilagem , Cartilagem Articular/metabolismo , Progressão da Doença , Exercício Físico/fisiologia , Feminino , Fêmur/patologia , História do Século XVII , Humanos , Masculino , Proteínas Matrilinas , Pessoa de Meia-Idade , Osteoartrite do Joelho/sangue , Estresse Mecânico , Tíbia/patologia
13.
Med Phys ; 39(4): 1769-78, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22482600

RESUMO

PURPOSE: The most appropriate method of evaluating the effective atomic number necessitates consideration of energy-dependent behavior. Previously, this required quite laborious calculation, which is why many scientists revert to over-simplistic power-law methods. The purpose of this work is to develop user-friendly software for the robust, energy-dependent computation of effective atomic numbers relevant within the context of medical physics, superseding the commonly employed simplistic power law approaches. METHOD: Visual Basic was used to develop a GUI allowing the straightforward calculation of effective atomic numbers. Photon interaction cross section matrices are constructed for energies spanning 10 keV to 10 GeV and elements Z = 1-100. Coefficients for composite media are constructed via linear additivity of the fractional constituents and contrasted against the precalculated matrices at each energy, thereby associating an effective atomic number through interpolation of adjacent cross section data. Uncertainties are of the order of 1-2%. RESULTS: Auto-Z(eff) allows rapid (∼0.6 s) calculation of effective atomic numbers for a range of predefined or user-specified media, allowing estimation of radiological properties and comparison of different media (for instance assessment of water equivalence). The accuracy of Auto-Z(eff) has been validated against numerous published theoretical and experimental predictions, demonstrating good agreement. The results also show that commonly employed power-law approaches are inaccurate, even in their intended regime of applicability (i.e., photoelectric regime). Furthermore, comparing the effective atomic numbers of composite materials using power-law approaches even in a relative fashion is shown to be inappropriate. CONCLUSION: Auto-Z(eff) facilitates easy computation of effective atomic numbers as a function of energy, as well as average and spectral-weighted means. The results are significantly more accurate than normal power-law predictions. The software is freely available to interested readers, who are encouraged to contact the authors.


Assuntos
Algoritmos , Modelos Químicos , Peso Molecular , Software , Espectrofotometria Atômica/métodos , Simulação por Computador
14.
Med Phys ; 39(4): 2203-13, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22482642

RESUMO

PURPOSE: Interfraction and intrafraction variation in anatomic structures is a significant challenge in contemporary radiotherapy. The objective of this work is to develop a novel tool for deformable structure dosimetry, using a tissue-equivalent deformable gel dosimeter that can reproducibly simulate targets subject to deformation. This will enable direct measurement of integrated doses delivered in different deformation states, and the verification of dose deforming algorithms. METHODS: A modified version of the nPAG polymer gel has been used as a deformable 3D dosimeter and phantom to investigate doses delivered to deforming tissue-equivalent geometry. The deformable gel (DEFGEL) dosimeter/phantom is comprised of polymer gel in a latex membrane, moulded (in this case) into a cylindrical geometry, and deformed with an acrylic compressor. Fifteen aluminium fiducial markers (FM) were implanted into DEFGEL phantoms and the reproducibility of deformation was determined via multiple computed tomography (CT) scans in deformed and nondeformed states before and after multiple (up to 150) deformations. Dose was delivered to the DEFGEL phantom in three arrangements: (i) without deformation, (ii) with deformation, and (iii) cumulative exposures with and without deformation, i.e., dose integration. Irradiations included both square field and a stereotactic multiple dynamic arc treatment adapted from a patient plan. Doses delivered to the DEFGEL phantom were read out using cone beam optical CT. RESULTS: Reproducibility was verified by observation of interscan shifts of FM locations (as determined via CT), measured from an absolute reference point and in terms of inter-FM distance. The majority (76%) of points exhibited zero shift, with others shifting by one pixel size consistent with setup error as confirmed with a control sample. Comparison of dose profiles and 2D isodose distributions from the three arrangements illustrated complex spatial redistribution of dose in all three dimensions occurring as a result of the change in shape of the target between irradiations, even for a relatively simple deformation. Discrepancies of up to 30% of the maximum dose were evident from dose difference maps for three orthogonal planes taken through the isocenter of a stereotactic field. CONCLUSIONS: This paper describes the first use of a tissue-equivalent, 3D dose-integrating deformable phantom that yields integrated or redistributed dosimetric information. The proposed methodology readily yields three-dimensional (3D) dosimetric data from radiation delivery to the DEFGEL phantom in deformed and undeformed states. The impacts of deformation on dose distributions were readily seen in the isodose contours and line profiles from the three arrangements. It is demonstrated that the system is potentially capable of reproducibly emulating the physical deformation of an organ, and therefore can be used to evaluate absorbed doses to deformable targets and organs at risk in three dimensions and to validate deformation algorithms applied to dose distributions.


Assuntos
Géis/química , Géis/efeitos da radiação , Radiometria/instrumentação , Tomografia Computadorizada por Raios X/métodos , Módulo de Elasticidade , Teste de Materiais , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
15.
Med Phys ; 39(8): 5065-72, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22894432

RESUMO

PURPOSE: Strategies for dose accumulation in deforming anatomy are of interest in radiotherapy. Algorithms exist for the deformation of dose based on patient image sets, though these are sometimes contentious because not all such image calculations are constrained by physical laws. While tumor and organ motion has been a key area of study for a considerable amount of time, deformation is of increasing interest. In this work, we demonstrate a full 3D experimental validation of results from a range of dose deformation algorithms available in the public domain. METHODS: We recently developed the first tissue-equivalent, full 3D deformable dosimetric phantom-"DEFGEL." To assess the accuracy of dose-warping based on deformable image registration (DIR), we have measured doses in undeformed and deformed states of the DEFGEL dosimeter and compared these to planned doses and warped doses. In this way we have directly evaluated the accuracy of dose-warping calculations for 11 different algorithms. We have done this for a range of stereotactic irradiation schemes and types and magnitudes of deformation. RESULTS: The original Horn and Schunck algorithm is shown to be the best performing of the 11 algorithms trialled. Comparing measured and dose-warped calculations for this method, it is found that for a 10 × 10 mm(2) square field, γ(3%∕3mm) = 99.9%; for a 20 × 20 mm(2) cross-shaped field, γ(3%∕3mm) = 99.1%; and for a multiple dynamic arc (0.413 cm(3) PTV) treatment adapted from a patient treatment plan, γ(3%∕3mm) = 95%. In each case, the agreement is comparable to-but consistently ∼1% less than-comparison between measured and calculated (planned) dose distributions in the absence of deformation. The magnitude of the deformation, as measured by the largest displacement experienced by any voxel in the volume, has the greatest influence on the accuracy of the warped dose distribution. Considering the square field case, the smallest deformation (∼9 mm) yields agreement of γ(3%∕3mm) = 99.9%, while the most significant deformation (∼20 mm) yields agreement of γ(3%∕3mm) = 96.7%. CONCLUSIONS: We have confirmed that, for a range of mass and density conserving deformations representative of those observable in anatomical targets, DIR-based dose-warping can yield accurate predictions of the dose distribution. Substantial differences can be seen between the results of different algorithms indicating that DIR performance should be scrutinized before application todose-warping. We have demonstrated that the DEFGEL deformable dosimeter can be used to evaluate DIR performance and the accuracy of dose-warping results by direct measurement.


Assuntos
Imageamento Tridimensional/métodos , Radiometria/métodos , Algoritmos , Elétrons , Géis/química , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imagens de Fantasmas , Fótons , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia Conformacional/métodos , Reprodutibilidade dos Testes
16.
J Dairy Sci ; 95(4): 1855-72, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22459833

RESUMO

Johne's disease, or paratuberculosis, is a chronic infectious enteric disease of ruminants, caused by infection with Mycobacterium avium ssp. paratuberculosis (MAP). Given the absence of a fail-safe method of prevention or a cure, Johne's disease can inflict significant economic loss on the US dairy industry, with an estimated annual cost of over $200 million. Currently available MAP control strategies include management measures to improve hygiene, culling MAP serologic- or fecal-positive adult cows, and vaccination. Although the 2 first control strategies have been reported to be effective in reducing the incidence of MAP infection, the changes in herd management needed to conduct these control strategies require significant effort on the part of the dairy producer. On the other hand, vaccination is relatively simple to apply and requires minor changes in herd management. Despite these advantages, only 5% of US dairy operations use vaccination to control MAP. This low level of adoption of this technology is due to limited information on its cost-effectiveness and efficacy and some important inherent drawbacks associated with current MAP vaccines. This study investigates the epidemiological effect and economic values of MAP vaccines in various stages of development. We create scenarios for the potential epidemiological effects of MAP vaccines, and then estimate economically justifiable monetary values at which vaccines become economically beneficial to dairy producers such that a net present value (NPV) of a farm's net cash flow can be higher than the NPV of a farm using no control or alternative nonvaccine controls. Any vaccination with either low or high efficacy considered in this study yielded a higher NPV compared with a no MAP control. Moreover, high-efficacy vaccines generated an even higher NPV compared with alternative controls, making vaccination economically attractive. Two high-efficacy vaccines were particularly effective in MAP control and NPV maximization. One was a high-efficacy vaccine that reduced susceptibility to MAP infection. The other was a high-efficacy vaccine that had multiple efficacies on the dynamics of MAP infection and disease progress. Only one high-efficacy vaccine, in which the vaccine is targeted at reducing MAP shedding and the number of clinical cases, was not economically beneficial to dairy producers compared with an alternative nonvaccine control, when herds were highly infected with MAP.


Assuntos
Vacinas Bacterianas/administração & dosagem , Indústria de Laticínios/economia , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/prevenção & controle , Animais , Vacinas Bacterianas/economia , Bovinos , Custos e Análise de Custo , Indústria de Laticínios/métodos , Transmissão de Doença Infecciosa/prevenção & controle , Transmissão de Doença Infecciosa/veterinária , Feminino , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Transmissão Vertical de Doenças Infecciosas/veterinária , Paratuberculose/transmissão , Vacinação/economia , Vacinação/veterinária
17.
J Med Entomol ; 59(2): 700-709, 2022 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-34875079

RESUMO

The range of ticks in North America has been steadily increasing likely, in part, due to climate change. Along with it, there has been a rise in cases of tick-borne disease. Among those medically important tick species of particular concern are Ixodes scapularis Say (Acari: Ixodidae), Dermacentor variabilis Say (Acari: Ixodidae), and Amblyomma americanum Linneaus (Acari: Ixodidae). The aim of this study was to determine if climate factors explain existing differences in abundance of the three aforementioned tick species between two climatically different regions of Illinois (Central and Southern), and if climate variables impact each species differently. We used both zero-inflated regression approaches and Bayesian network analyses to assess relationships among environmental variables and tick abundance. Results suggested that the maximum average temperature and total precipitation are associated with differential impact on species abundance and that this difference varied by region. Results also reinforced a differential level of resistance to desiccation among these tick species. Our findings help to further define risk periods of tick exposure for the general public, and reinforce the importance of responding to each tick species differently.


Assuntos
Ixodes , Ixodidae , Amblyomma , Animais , Teorema de Bayes , Illinois
18.
Osteoarthritis Cartilage ; 19(2): 171-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21112409

RESUMO

OBJECTIVE: A relationship between T1ρ relaxation time and glycosaminoglycan (GAG) content has been demonstrated in chemically degraded bovine cartilage, but has not been demonstrated with quantitative biochemistry in human cartilage. A relationship has also been established between T2 relaxation time in cartilage and osteoarthritis (OA) severity. We hypothesized that T1ρ relaxation time would be associated with GAG content in human cartilage with normal T2 relaxation times. METHODS: T2 relaxation time, T1ρ relaxation time, and glycosaminoglycan as a percentage of wet weight (sGAG) were measured for top and bottom regions at 7 anatomical locations in 21 human cadaver patellae. For our analysis, T2 relaxation time was classified as normal or elevated based on a threshold defined by the mean plus one standard deviation of the T2 relaxation time for all samples. RESULTS: In the normal T2 relaxation time subset, T1ρ relaxation time correlated with sGAG content in the full-thickness and bottom regions, but only marginally in the top region alone. sGAG content decreased significantly with age in all regions. CONCLUSION: In the subset of cartilage specimens with normal T2 relaxation time, T1ρ relaxation time was inversely associated with sGAG content, as hypothesized. A predictive model, which accounts for T2 relaxation time and the effects of age, might be able to determine longitudinal trends in GAG content in the same person based on T1ρ relaxation time maps.


Assuntos
Cartilagem Articular/química , Cartilagem Articular/patologia , Glicosaminoglicanos/análise , Imageamento por Ressonância Magnética/métodos , Patela/química , Patela/patologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/diagnóstico , Valor Preditivo dos Testes , Adulto Jovem
19.
Br J Dermatol ; 164(3): 660-4, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21375519

RESUMO

BACKGROUND: Many autoimmune diseases share common susceptibility loci suggesting similar underlying cellular mechanisms involved in disease expression. OBJECTIVES: The purpose of this investigation was to study 21 genetic variants in 14 genes that are confirmed autoimmune loci in a cohort of patients with early-onset psoriasis. METHODS: Patients with early-onset psoriasis (n = 750) and controls (n = 3531) were genotyped using the Sequenom(®) MassArray™ iPLEX Gold platform. RESULTS: We found strong evidence of association with two variants in the IL2/IL21 (rs6822844, genotypic P = 3·3 × 10(-4) ; rs2069778, genotypic P = 7·86 × 10(-4)) region. CONCLUSIONS: The findings, although requiring replication, suggest that IL2/IL21 may play a key role in the pathogenesis of psoriasis as well as in other diverse autoimmune diseases.


Assuntos
Interleucina-2/genética , Interleucinas/genética , Psoríase/genética , Adolescente , Adulto , Idade de Início , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética , Psoríase/imunologia , Adulto Jovem
20.
Aust Vet J ; 99(12): 541-546, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34569052

RESUMO

Objective comparative evidence of the time to onset and duration of effect provided by local anaesthetic (LA) agents for perineural blocks in the horse is lacking. Clear knowledge of these properties is required to guide clinically appropriate agent selection and aid interpretation of response to diagnostic blocks for lameness examinations. An interventional study, with complete, randomised crossover design was used to compare time to onset and duration of skin desensitisation provided by four LA agents applied to palmar digital nerve blocks in 12 horses. Effect at each time point was determined using a pressure gauge to measure the mechanical nociceptive threshold (MNT) over the heel bulbs. Complete desensitisation was defined when MNT was greater than four times the pre-block baseline. Onset and duration of complete desensitisation were recorded and compared across agents using a mixed linear model. When significant (P ≤ 0.05), post-hoc paired comparisons between agents were performed against a Tukey's corrected P ≤ 0.05. Onset of complete skin desensitisation for each agent was <5 min. Duration for lidocaine (mean 25 min; 95% confidence interval [CI] 9-42) was shorter than bupivacaine (53 min; 95% CI 39-65), which was shorter than both prilocaine (102 min; 95% CI 81-123) and mepivacaine (107 min; 95% CI 92-121), which were not different. Although onset of complete skin desensitisation was not different for the LA agents tested, duration varied from 25 min to nearly 2 h. Prilocaine and mepivacaine provided the most prolonged duration of effect, both exceeding bupivacaine.


Assuntos
Mepivacaína , Bloqueio Nervoso , Anestésicos Locais/efeitos adversos , Animais , Bupivacaína , Cavalos , Lidocaína/efeitos adversos , Bloqueio Nervoso/veterinária , Prilocaína
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