Relación entre el valor del ratio elastográfico y la clasificación citológica de Bethesda en la patología tiroidea

ResumenObjetivoPresentar nuestra experiencia en la categorización de la patología tiroidea, a través de la utilización de parámetros ecográficos de malignidad y elastografía con medición del ratio de la deformación tisular, y la correlación de los hallazgos obtenidos con la clasificación citológica de Bethesda.Materiales y métodosSe llevó a cabo un estudio prospectivo y observacional, entre septiembre de 2012 y abril de 2013, que incluyó 137 nódulos tiroideos. Se excluyeron 10 casos Bethesda III-IV. Se realizó ecografía, power Doppler, visualización de micropartículas (Micropure) y elastografía con medición del ratio elastográfico, así como también punción aspirativa con aguja fina guiada por ecografía (con el citólogo presente), utilizando la clasificación Bethesda. Los estudios fueron hechos por el mismo operador con un ecógrafo Toshiba Aplio 400 y los datos estadísticos se evaluaron con el programa IBM SPSS Statistics 20.ResultadosSe estudiaron 127 nódulos en pacientes con una edad promedio de 59±16 años. El 82% de los casos ocurrió en mujeres. Ciento veinte nódulos (94%) fueron clasificados como Bethesda II. La media elastográfica para Bethesda I-II fue de 1,94±2,12 vs. 7,07±5,46 para V-VI (p: 0,048). El punto de corte elastográfico ≤ 2 (87 de 127) presentó una sensibilidad del 85,7% y una especificidad del 81,7% para predecir Bethesda asociada a patología benigna, con un valor predictivo negativo (VPN) del 99% y un valor predictivo positivo del 15%.ConclusionesEl ratio elastográfico permitió descartar la patología tiroidea maligna con valores ≤ 2 y un VPN del 99%, mejorando la selección de los pacientes a punzar. El incremento del ratio elastográfico se asoció a una mayor probabilidad de patología maligna, aunque no se pudo establecer un valor de corte debido al bajo número de casos con Bethesda V-VI.AbstractObjectivesWe present our experience in the categorization of thyroid pathology using the sonographic parameters of malignancy and elastography with measurement elastography strain ratio, to evaluate the relationship between the results found and the Bethesda classification.Materials and methodsProspective observational study, included 137 thyroid nodules studied between September 2012- April 2013. We excluded 10 cases with Bethesda categories III-IV. Ultrasonography, Doppler, Micropure, elastogrphy strain ratio between the lesion and the normal tissue, fine needle aspiration cytology (FNAC),were the diagnosis methods used. The pathologist was always present and the cytological classi fication of Bethesda was used. All study was made by the same physician used Toshiba Aplio 400 ultrasound unit. Results were analyzed with IBM SPSS Statistics 20.ResultsWe studied 127 nodules in patients 59±16 years old, 82% were female; 120 were Bethesda II (94%). The average strain ratio for nodules Bethesda I-II was 1.94±2.12 vs. 7.07±5.46 for those nodules Bethesda V-VI (p:0,048). This means that an elastography strain ratio ≤ 2 (87 of 127 nodules) has a sensibility of 85.7% and a specificity of 81.7% of predicting Bethesda associated with benign pathology with a negative predictive value (NPV) of 99% and a positive predictive value of 15%.ConclusionThe elastography strain ratio allowed to discard malignant nodules with strain ratio ≤ 2 with a NPV of 99% improves the selection of patients for FNAC. The increment in the elastography strain ratio was associated to a higher possibility of malignant thyroid pathology, being unable to determine a limit value due to the low amount of cases with nodules Bethesda V-VI

Improving the Cost-efficiency of Preventive Chemotherapy : Impact of New Diagnostics on Stopping Decisions for Control of Schistosomiasis

BackgroundControl of schistosomiasis (SCH) relies on the regular distribution of preventive chemotherapy (PC) over many years. For the sake of sustainable SCH control, a decision must be made at some stage to scale down or stop PC. These "stopping decisions" are based on population surveys that assess whether infection levels are sufficiently low. However, the limited sensitivity of the currently used diagnostic (Kato-Katz [KK]) to detect low-intensity infections is a concern. Therefore, the use of new, more sensitive, molecular diagnostics has been proposed.MethodsThrough statistical analysis of Schistosoma mansoni egg counts collected from Burundi and a simulation study using an established transmission model for schistosomiasis, we investigated the extent to which more sensitive diagnostics can improve decision making regarding stopping or continuing PC for the control of S. mansoni.ResultsWe found that KK-based strategies perform reasonably well for determining when to stop PC at a local scale. Use of more sensitive diagnostics leads to a marginally improved health impact (person-years lived with heavy infection) and comes at a cost of continuing PC for longer (up to around 3 years), unless the decision threshold for stopping PC is adapted upward. However, if this threshold is set too high, PC may be stopped prematurely, resulting in a rebound of infection levels and disease burden (+45% person-years of heavy infection).ConclusionsWe conclude that the potential value of more sensitive diagnostics lies more in the reduction of survey-related costs than in the direct health impact of improved parasite control

Improving the Cost-efficiency of Preventive Chemotherapy: Impact of New Diagnostics on Stopping Decisions for Control of Schistosomiasis

BACKGROUND: Control of schistosomiasis (SCH) relies on the regular distribution of preventive chemotherapy (PC) over many years. For the sake of sustainable SCH control, a decision must be made at some stage to scale down or stop PC. These "stopping decisions" are based on population surveys that assess whether infection levels are sufficiently low. However, the limited sensitivity of the currently used diagnostic (Kato-Katz [KK]) to detect low-intensity infections is a concern. Therefore, the use of new, more sensitive, molecular diagnostics has been proposed. METHODS: Through statistical analysis of Schistosoma mansoni egg counts collected from Burundi and a simulation study using an established transmission model for schistosomiasis, we investigated the extent to which more sensitive diagnostics can improve decision making regarding stopping or continuing PC for the control of S. mansoni. RESULTS: We found that KK-based strategies perform reasonably well for determining when to stop PC at a local scale. Use of more sensitive diagnostics leads to a marginally improved health impact (person-years lived with heavy infection) and comes at a cost of continuing PC for longer (up to around 3 years), unless the decision threshold for stopping PC is adapted upward. However, if this threshold is set too high, PC may be stopped prematurely, resulting in a rebound of infection levels and disease burden (+45% person-years of heavy infection). CONCLUSIONS: We conclude that the potential value of more sensitive diagnostics lies more in the reduction of survey-related costs than in the direct health impact of improved parasite control

The effect of fight cost structure on fighting behaviour involving simultaneous decisions and variable investment levels

In the “producer–scrounger” model, a producer discovers a resource and is in turn discovered by a second individual, the scrounger, who attempts to steal it. This resource can be food or a territory, and in some situations, potentially divisible. In a previous paper we considered a producer and scrounger competing for an indivisible resource, where each individual could choose the level of energy that they would invest in the contest. The higher the investment, the higher the probability of success, but also the higher the costs incurred in the contest. In that paper decisions were sequential with the scrounger choosing their strategy before the producer. In this paper we consider a version of the game where decisions are made simultaneously. For the same cost functions as before, we analyse this case in detail, and then make comparisons between the two cases. Finally we discuss some real examples with potentially variable and asymmetric energetic investments, including intraspecific contests amongst spiders and amongst parasitoid wasps. In the case of the spiders, detailed estimates of energetic expenditure are available which demonstrate the asymmetric values assumed in our models. For the wasps the value of the resource can affect the probabilities of success of the defender and attacker, and differential energetic investment can be inferred. In general for real populations energy usage varies markedly depending upon crucial parameters extrinsic to the individual such as resource value and intrinsic ones such as age, and is thus an important factor to consider when modelling

River water quality assessment using environmentric techniques : case study of Jakara River Basin.

akara River Basin has been extensively studied to assess the overall water quality and to identify the major variables responsible for water quality variations in the basin. A total of 27 sampling points were selected in the riverine network of the Upper Jakara River Basin. Water samples were collected in triplicate and analyzed for physicochemical variables. Pearson product-moment correlation analysis was conducted to evaluate the relationship of water quality parameters and revealed a significant relationship between salinity, conductivity with dissolved solids (DS) and 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and nitrogen in form of ammonia (NH4). Partial correlation analysis (r p) results showed that there is a strong relationship between salinity and turbidity (r p = 0.930, p = 0.001) and BOD5 and COD (r p = 0.839, p = 0.001) controlling for the linear effects of conductivity and NH4, respectively. Principal component analysis and or factor analysis was used to investigate the origin of each water quality parameter in the Jakara Basin and identified three major factors explaining 68.11 % of the total variance in water quality. The major variations are related to anthropogenic activities (irrigation agricultural, construction activities, clearing of land, and domestic waste disposal) and natural processes (erosion of river bank and runoff). Discriminant analysis (DA) was applied on the dataset to maximize the similarities between group relative to within-group variance of the parameters. DA provided better results with great discriminatory ability using eight variables (DO, BOD5, COD, SS, NH4, conductivity, salinity, and DS) as the most statistically significantly responsible for surface water quality variation in the area. The present study, however, makes several noteworthy contributions to the existing knowledge on the spatial variations of surface water quality and is believed to serve as a baseline data for further studies. Future research should therefore concentrate on the investigation of temporal variations of water quality in the basin

Modelling Dominance Hierarchies Under Winner and Loser Effects

Animals that live in groups commonly form themselves into dominance hierarchies which are used to allocate important resources such as access to mating opportunities and food. In this paper, we develop a model of dominance hierarchy formation based upon the concept of winner and loser effects using a simulation-based model and consider the linearity of our hierarchy using existing and new statistical measures. Two models are analysed: when each individual in a group does not know the real ability of their opponents to win a fight and when they can estimate their opponents' ability every time they fight. This estimation may be accurate or fall within an error bound. For both models, we investigate if we can achieve hierarchy linearity, and if so, when it is established. We are particularly interested in the question of how many fights are necessary to establish a dominance hierarchy

Conceptual Framework on Workplace Deviance Behavior: A Review

This article aims to highlight the importance of organizational climate with both destructive and constructive deviance behaviour in different cultural setting with workplace as a common ground. First, we discuss the need for research in workplace deviance especially destructive and constructive deviance behaviour with the review of previous studies from deviance literature. Next, we present the importance of climate and culture with both destructive and constructive deviance by proposing relationship among them with the help of a framework. The presented theoretical framework can be useful for conducting future empirical research. Finally, we present the conclusion and future research in conducting cross-national research with respect to deviance

Pulsed electromagnetic fields after arthroscopic treatment for osteochondral defects of the talus: double-blind randomized controlled multicenter trial

Background. Osteochondral talar defects usually affect athletic patients. The primary surgical treatment consists of arthroscopic debridement and microfracturing. Although this is mostly successful, early sport resumption is difficult to achieve, and it can take up to one year to obtain clinical improvement. Pulsed electromagnetic fields (PEMFs) may be effective for talar defects after arthroscopic treatment by promoting tissue healing, suppressing inflammation, and relieving pain. We hypothesize that PEMF-treatment compared to sham-treatment after arthroscopy will lead to earlier resumption of sports, and aim at 25% increase in patients that resume sports. Methods/Design. A prospective, double-blind, randomized, placebo-controlled trial (RCT) will be conducted in five centers throughout the Netherlands and Belgium. 68 patients will be randomized to either active PEMF-treatment or sham-treatment for 60 days, four hours daily. They will be followed-up for one year. The combined primary outcome measures are (a) the percentage of patients that resume and maintain sports, and (b) the time to resumption of sports, defined by the Ankle Activity Score. Secondary outcome measures include resumption of work, subjective and objective scoring systems (American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale, Foot Ankle Outcome Score, Numeric Rating Scales of pain and satisfaction, EuroQol-5D), and computed tomography. Time to resumption of sports will be analyzed using Kaplan-Meier curves and log-rank tests. Discussion. This trial will provide level-1 evidence on the effectiveness of PEMFs in the management of osteochondral ankle lesions after arthroscopy. Trial registration. Netherlands Trial Register (NTR1636)