Left ventricular thrombus attenuation characterization in cardiac computed tomography angiography

BACKGROUND: Because of their similar visual appearance, differentiation of left ventricular thrombotic material and myocardial wall can be difficult in contrast-enhanced coronary computed tomography (CT) angiography. OBJECTIVE: We identified typical thrombi attenuation of left ventricular thrombi with the use of CT measurement. METHODS: Over a time period of 6 years; we retrospectively identified 31 patients who showed a left ventricular thrombus in CT angiography datasets. Patients underwent routine contrast cardiac CT to investigate coronary artery disease. CT attenuation of each thrombus was assessed in the 4-chamber view. CT densities were also determined in the ascending aorta, left ventricle, and myocardial wall both in the mid-septal and mid-lateral segments. The mean CT attenuation of thrombi and the difference between attenuation in thrombi, left ventricular cavity, and myocardial wall were determined. The ratio of attenuation values in thrombus versus aorta and myocardium versus aorta were also determined. RESULTS: Mean (+/- SD) CT attenuation of all left ventricular thrombi in 31 patients was 43.2 +/- 15.3 HU (range, 25-80 HU). Mean CT densities of septal and lateral myocardial wall were 102.9 +/- 23.1 HU (range, 63-155 HU) and 99.3 +/- 28.7 HU (range, 72-191 HU), respectively, and were thus significantly higher than the CT attenuation of thrombi (P < 0.001). A threshold of 65 HU yielded a sensitivity, specificity, and positive and negative predictive values of 94%, 97%, 94%, and 97%, respectively, to differentiate thrombus from the myocardial wall. The mean ratio between CT attenuation of thrombus and CT attenuation within the ascending aorta was 0.11 +/- 0.05 (range, 0.04-0.23), which was significantly lower compared with the mean ratio between CT attenuation of the myocardial wall and the CT attenuation within the ascending aorta. CONCLUSION: CT attenuation within left ventricular thrombi was significantly lower than myocardial attenuation in CT angiography datasets. Assessment of CT attenuation may contribute to the differentiation of thrombi. (C) 2012 Society of Cardiovascular Computed Tomography. All rights reserved.

Ensino de anestesiologia durante a graduação por meio de uma liga acadêmica: qual o impacto no aprendizado dos alunos?

Justificativa e objetivos: As ligas acadêmicas vêm se firmando como instrumentos de ensino médico e inserção dos estudantes de medicina na prática das especialidades, inclusive na anestesiologia. Como o papel das ligas no processo de desenvolvimento de competências e aprendizado de seus alunos não é bem conhecido, avaliou-se o aprendizado dos integrantes de uma liga acadêmica de anestesiologia após um ano de participação nas suas atividades. MÉTODO: Os alunos de uma liga acadêmica de anestesiologia foram acompanhados de março a dezembro de 2010 e avaliados por meio de testes cognitivos objetivos de múltipla escolha aplicados antes do início das atividades e após sua conclusão. A frequência nas atividades e o perfil epidemiológico dos alunos foram correlacionados aos resultados dos testes. RESULTADOS: Foram analisados 20 acadêmicos do 3º ao 6º ano, com média de idade de 22,8 (21-26) anos. A frequência média nas atividades propostas foi 10,4/13 (80%). A média de acertos no primeiro teste foi 8,1/17 (47,6%), sendo que os alunos do 3º ano apresentam notas menores (p < 0,02) em relação aos demais. No teste pós-liga, a média de acertos foi 11,9/17 (70%), mostrando melhora no desempenho dos alunos (p < 0,05), e não houve diferença entre as notas dos diferentes anos da graduação. Foi encontrada relação forte entre frequência nas atividades e melhora nas notas (r = 0,719; p < 0,001). CONCLUSÕES: Os alunos que participaram da liga apresentaram melhora nos testes de avaliação de conhecimento, sugerindo que a liga é útil instrumento de ensino e promove ganho de aprendizado em anestesiologia. As atividades desenvolvidas nas ligas podem ter papel positivo na formação acadêmica dos graduandos, destacando-se, neste artigo, a anestesiologia.

Ensino de anestesiologia durante a graduação por meio de uma liga acadêmica: qual o impacto no aprendizado dos alunos?

JUSTIFICATIVA E OBJETIVOS: As ligas acadêmicas vêm se firmando como instrumentos de ensino médico e inserção dos estudantes de medicina na prática das especialidades, inclusive na anestesiologia. Como o papel das ligas no processo de desenvolvimento de competências e aprendizado de seus alunos não é bem conhecido, avaliou-se o aprendizado dos integrantes de uma liga acadêmica de anestesiologia após um ano de participação nas suas atividades. MÉTODO: Os alunos de uma liga acadêmica de anestesiologia foram acompanhados de março a dezembro de 2010 e avaliados por meio de testes cognitivos objetivos de múltipla escolha aplicados antes do início das atividades e após sua conclusão. A frequência nas atividades e o perfil epidemiológico dos alunos foram correlacionados aos resultados dos testes. RESULTADOS: Foram analisados 20 acadêmicos do 3º ao 6º ano, com média de idade de 22,8 (21-26) anos. A frequência média nas atividades propostas foi 10,4/13 (80%). A média de acertos no primeiro teste foi 8,1/17 (47,6%), sendo que os alunos do 3º ano apresentam notas menores (p < 0,02) em relação aos demais. No teste pós-liga, a média de acertos foi 11,9/17 (70%), mostrando melhora no desempenho dos alunos (p < 0,05), e não houve diferença entre as notas dos diferentes anos da graduação. Foi encontrada relação forte entre frequência nas atividades e melhora nas notas (r = 0,719; p < 0,001). CONCLUSÕES: Os alunos que participaram da liga apresentaram melhora nos testes de avaliação de conhecimento, sugerindo que a liga é útil instrumento de ensino e promove ganho de aprendizado em anestesiologia. As atividades desenvolvidas nas ligas podem ter papel positivo na formação acadêmica dos graduandos, destacando-se, neste artigo, a anestesiologia

Evaluation of reference-based two-color methods for measurement of gene expression ratios using spotted cDNA microarrays

Abstract Background Spotted cDNA microarrays generally employ co-hybridization of fluorescently-labeled RNA targets to produce gene expression ratios for subsequent analysis. Direct comparison of two RNA samples in the same microarray provides the highest level of accuracy; however, due to the number of combinatorial pair-wise comparisons, the direct method is impractical for studies including large number of individual samples (e.g., tumor classification studies). For such studies, indirect comparisons using a common reference standard have been the preferred method. Here we evaluated the precision and accuracy of reconstructed ratios from three indirect methods relative to ratios obtained from direct hybridizations, herein considered as the gold-standard. Results We performed hybridizations using a fixed amount of Cy3-labeled reference oligonucleotide (RefOligo) against distinct Cy5-labeled targets from prostate, breast and kidney tumor samples. Reconstructed ratios between all tissue pairs were derived from ratios between each tissue sample and RefOligo. Reconstructed ratios were compared to (i) ratios obtained in parallel from direct pair-wise hybridizations of tissue samples, and to (ii) reconstructed ratios derived from hybridization of each tissue against a reference RNA pool (RefPool). To evaluate the effect of the external references, reconstructed ratios were also calculated directly from intensity values of single-channel (One-Color) measurements derived from tissue sample data collected in the RefOligo experiments. We show that the average coefficient of variation of ratios between intra- and inter-slide replicates derived from RefOligo, RefPool and One-Color were similar and 2 to 4-fold higher than ratios obtained in direct hybridizations. Correlation coefficients calculated for all three tissue comparisons were also similar. In addition, the performance of all indirect methods in terms of their robustness to identify genes deemed as differentially expressed based on direct hybridizations, as well as false-positive and false-negative rates, were found to be comparable. Conclusion RefOligo produces ratios as precise and accurate as ratios reconstructed from a RNA pool, thus representing a reliable alternative in reference-based hybridization experiments. In addition, One-Color measurements alone can reconstruct expression ratios without loss in precision or accuracy. We conclude that both methods are adequate options in large-scale projects where the amount of a common reference RNA pool is usually restrictive.

Intervention to reduce C-reactive protein determination requests for acute infections at an emergency department

Introduction C-reactive protein (CRP) levels rise during inflammatory processes and have been ordered for rheumatic disease follow-up since the 1950s. The number of tests ordered in the emergency setting has increased, but without evident improvement in medical care quality. Objective To determine the pattern of CRP determinations in the emergency department (ED) of a university hospital in Sao Paulo, Brazil, and to evaluate the effect of an intervention with staff and students about the best use of the test in the ED. Methods Data regarding CRP testing requests, related diagnoses and the number of monthly consultations in the hospital ED were analysed before and after the intervention. Because of an increase in CRP measurement requests from 2007 to 2009, the author started discussing the role of CRP determinations in the medical decision-making process in early 2010. Staff and faculty members openly discussed the pattern of requests in the hospital and related current medical literature. During 2010, the medical staff worked as multipliers to change the behaviour of new students and residents. The results of the first 4 months after the intervention were presented at another general meeting in July 2010. Results From 2007 to 2009, there were 11 786 CRP measurement requests with a clear exponential trend. After the intervention, during the calendar year 2010, there was a 48% reduction in adjusted annual CRP requests. Pneumonia, fever and urinary tract infections were the most common reasons for CRP requests. Discussion Inexpensive, well-directed, interactive educational interventions may affect professional behaviour and curb rates of laboratory tests.

Urban Air Pollutants are Significant Risk Factors for Asthma and Pneumonia in Children: The Influence of Location on the Measurement of Pollutants

Background: Air pollution is associated with a substantial burden on human health; however, the most important pollutants may vary with location. Proper monitoring is necessary to determine the effect of these pollutants on respiratory health. Objectives: This study was designed to evaluate the role of outdoor, indoor and personal exposure to combustion-related pollutants NO2 and O-3 on respiratory health of children in a non-affluent urban area of Sao Paulo, Brazil. Methods: Levels of NO2 and O-3 were continuously measured in outdoor and indoor air, as well as personal exposure, for 30 days using passive measurement monitors. Respiratory health was assessed with a Brazilian version of the ISAAC questionnaire. Results: Complete data were available from 64 children, aged 6-10 years. Respiratory morbidity was high, with 43 (67.2%) reporting having had wheezing at any time, 27 (42.2%) wheezing in the last month, 17 (26.6%) asthma at any time and 21(32.8%) pneumonia at any time. Correlations between levels of NO2 and O-3 measured in the three locations evaluated were poor. Levels of NO2 in indoor air and personal exposure to O-3 were independently associated with asthma (both cases P=.02), pneumonia (O-3, P=.02) and wheezing at any time (both cases P<.01). No associations were seen between outdoor NO2 and O-3 and respiratory health. Conclusions: Exposure to higher levels of NO2 and O-3 was associated with increased risk for asthma and pneumonia in children. Nonetheless, the place where the pollutants are measured influences the results. The measurements taken in indoor and personal exposure were the most accurate. (C) 2012 SEPAR. Published by Elsevier Espana, S.L. All rights reserved.

Measurement of buccal bone volume of dental implants by means of cone-beam computed tomography

Purpose: The aim of this study was to evaluate the accuracy of cone-beam computed tomography (CBCT) for measuring the buccal bone volume around dental implants. Materials and methods: Three to six implants were inserted into the anterior maxilla of eight skulls, depending on the availability of bone, and after this, the CBCT was performed. By means of CBCT image, measurements of the bone wall at three points of the implant were obtained, analyzed and compared with those obtained in the plaster skull casting. Results: The results showed that for the three points of the implants, no statistically significant difference in the measurements was obtained from the plaster model and CBCT images. Conclusions: CBCT can be a useful tool for assessing buccal bone volume along the implant. To cite this article:?Shiratori LN, Marotti J, Yamanouchi J, Chilvarquer I, Contin I, Tortamano-Neto P. Measurement of buccal bone volume of dental implants by means of cone-beam computed tomography.?Clin. Oral Impl. Res. 23, 2012; 797804.?doi: 10.1111/j.1600-0501.2011.02207.x

Further investigating the determination of phosphorus in plants by INAA using bremsstrahlung measurement

Phosphorus is an essential element for plants and animals, playing a fundamental role in the production of biochemical energy. Despite its relevance, phosphorus is not commonly determined by instrumental neutron activation analysis (INAA), because (32)P does not emit gamma-rays in its decay. There are alternative methods for the determination of phosphorus by INAA, such as the use of beta counting or the measurement of bremsstrahlung originated from the high energy beta particle from (32)P. Here the determination of phosphorus in plant materials by measuring the bremsstrahlung production was further investigated, to optimize an analytical protocol for minimizing interferences and overcoming the poor specificity. Eight certified reference materials of plant matrices with phosphorus ranging between 171 and 5,180 mg kg(-1) were irradiated at a thermal neutron flux of 9.5 x 10(12) cm(-2) s(-1) and measured with a HPGe detector at decay times varying from 7 to 60 days. Phosphorus solutions added to a certified reference material at three levels were used for calibration. Counts accumulated in the baseline at four different regions of the gamma-ray spectra were tested for the determination of phosphorus, with better results for the 100 keV region. The Compton scattering contribution in the selected range was discounted using an experimental peak-to-Compton factor and the net areas of all peaks in the spectra with energies higher than 218 keV, i.e. Compton edge above 100 keV. Amongst the interferences investigated, the production of (32)P from sulfur, and the contribution of Compton scattering should be considered for producing good results.

The impact of structured teaching methods on the quality of education in Brazil

This paper estimates the impact of the use of structured methods on the quality of education for students in primary public school in Brazil. Structured methods encompass a range of pedagogical and managerial instruments applied in the educational system. In recent years, several municipalities in the state of Sao Paulo have contracted out private educational providers to implement these structured methods in their schooling systems. Their pedagogical proposal involves structuring of curriculum content, development of teacher and student textbooks, and the training and supervision of teachers anti instructors. Using a difference-in-differences estimation strategy, we find that the 4th- and 8th-grade students in the municipalities with structured methods performed better in Portuguese and mathematics than did students in municipalities not exposed to these methods. We find no differences in passing rates. A robustness test supports the assumption that there is no unobserved municipal characteristics associated with proficiency changes over time that may affect the results. (C) 2012 Elsevier Ltd. All rights reserved.

Cognitive Training and Educational Intervention for Individuals with Hypertension: Effects on Cognition

Objectives: To evaluate the possibility of combining cognitive training to an educational intervention composed by eight sessions about hypertension for a better management of the disease among the elderly. Methods: 64 older adults who reported having hypertension, divided into experimental group (EG, n=35) and control group (CG, n=29) participated in the study. Control participants received training after the post-test. The protocol contained socio-demographic and clinical data, Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), Rivermead Behavioral Memory Test (RBMT), Verbal Fluency Animal Category (VF) and Short Cognitive Test (SKT). Results: The EG showed better cognitive performance when compared with the CG, at post-test. Conclusion: Cognitive gains may occur after psychoeducational interventions for older adults with hypertension.

In vivo accuracy of conventional and digital radiographic methods in confirming root canal working length determination by Root ZX

Objectives: To compare, in vivo, the accuracy of conventional and digital radiographic methods in determining root canal working length. Material and Methods: Twenty-five maxillary incisor or canine teeth from 22 patients were used in this study. Considering the preoperative radiographs as the baseline, a 25 K file was inserted into the root canal to the point where the Root ZX electronic apex locator indicated the APEX measurement in the screen. From this measurement, 1 mm was subtracted for positioning the file. The radiographic measurements were made using a digital sensor (Digora 1.51) or conventional type-E films, size 2, following the paralleling technique, to determine the distance of the file tip and the radiographic apex. Results: The Student "t" test indicated mean distances of 1.11 mm to conventional and 1.20 mm for the digital method and indicated a significant statistical difference (p<0.05). Conclusions: The conventional radiographic method was found to be superior to the digital one in determining the working length of the root canal.

Precision of Usual Food Intake Estimates According to the Percentage of Individuals with a Second Dietary Measurement

Background Statistical methods for estimating usual intake require at least two short-term dietary measurements in a subsample of the target population. However, the percentage of individuals with a second dietary measurement (replication rate) may influence the precision of estimates, such as percentiles and proportions of individuals below cut-offs of intake. Objective To investigate the precision of the usual food intake estimates using different replication rates and different sample sizes. Participants/setting Adolescents participating in the continuous National Health and Nutrition Examination Survey 2007-2008 (n=1,304) who completed two 24-hour recalls. Statistical analyses performed The National Cancer Institute method was used to estimate the usual intake of dark green vegetables in the original sample comprising 1,304 adolescents with a replication rate of 100%. A bootstrap with 100 replications was performed to estimate CIs for percentiles and proportions of individuals below cut-offs of intake. Using the same bootstrap replications, four sets of data sets were sampled with different replication rates (80%, 60%, 40%, and 20%). For each data set created, the National Cancer Institute method was performed and percentiles, Cl, and proportions of individuals below cut-offs were calculated. Precision estimates were checked by comparing each Cl obtained from data sets with different replication rates with the Cl obtained from original data set. Further, we sampled 1,000, 750, 500, and 250 individuals from the original data set, and performed the same analytical procedures. Results Percentiles of intake and percentage of individuals below the cut-off points were similar throughout the replication rates and sample sizes, but the Cl increased as the replication rate decreased. Wider CIs were observed at 40% and 20% of replication rate. Conclusions The precision of the usual intake estimates decreased when low replication rates were used. However, even with different sample sizes, replication rates >40% may not lead to an important loss of precision. J Acad Nutr Diet. 2012;112:1015-1020.

Origin of the heavy elements in HD 140283 Measurement of europium abundance

Context. HD 140283 is a nearby (V = 7.7) subgiant metal-poor star, extensively analysed in the literature. Although many spectra have been obtained for this star, none showed a signal-to-noise (S/N) ratio high enough to enable a very accurate derivation of abundances from weak lines. Aims. The detection of europium proves that the neutron-capture elements in this star originate in the r-process, and not in the s-process, as recently claimed in the literature. Methods. Based on the OSMARCS 1D LTE atmospheric model and with a consistent approach based on the spectrum synthesis code Turbospectrum, we measured the europium lines at 4129 angstrom and 4205 angstrom, taking into account the hyperfine structure of the transitions. The spectrum, obtained with a long exposure time of seven hours at the Canada-France-Hawaii Telescope (CFHT), has a resolving power of 81 000 and a S/N ratio of 800 at 4100 angstrom. Results. We were able to determine the abundance A(Eu) = -2.35 +/- 0.07 dex, compatible with the value predicted for the europium from the r-process. The abundance ratio [Eu/Ba] = +0.58 +/- 0.15 dex agrees with the trend observed in metal-poor stars and is also compatible with a strong r-process contribution to the origin of the neutron-capture elements in HD 140283.

Utility Harmonic Impedance Measurement Based on Data Selection

Determination of the utility harmonic impedance based on measurements is a significant task for utility power-quality improvement and management. Compared to those well-established, accurate invasive methods, the noninvasive methods are more desirable since they work with natural variations of the loads connected to the point of common coupling (PCC), so that no intentional disturbance is needed. However, the accuracy of these methods has to be improved. In this context, this paper first points out that the critical problem of the noninvasive methods is how to select the measurements that can be used with confidence for utility harmonic impedance calculation. Then, this paper presents a new measurement technique which is based on the complex data-based least-square regression, combined with two techniques of data selection. Simulation and field test results show that the proposed noninvasive method is practical and robust so that it can be used with confidence to determine the utility harmonic impedances.

Molecular measurement of BCR-ABL transcript variations in chronic myeloid leukemia patients in cytogenetic remission

Abstract Background The monitoring of BCR-ABL transcript levels by real-time quantitative polymerase chain reaction (RT-qPCR) has become important to assess minimal residual disease (MRD) and standard of care in the treatment of chronic myeloid leukemia (CML). In this study, we performed a prospective, sequential analysis using RT-qPCR monitoring of BCR-ABL gene rearrangements in blood samples from 91 CML patients in chronic phase (CP) who achieved complete cytogenetic remission (CCyR) and major molecular remission (MMR) throughout imatinib treatment. Methods The absolute level of BCR-ABL transcript from peripheral blood was serially measured every 4 to 12 weeks by RT-qPCR. Only level variations > 0.5%, according to the international scale, was considered positive. Sequential cytogenetic analysis was also performed in bone marrow samples from all patients using standard protocols. Results Based on sequential analysis of BCR-ABL transcripts, the 91 patients were divided into three categories: (A) 57 (62.6%) had no variation on sequential analysis; (B) 30 (32.9%) had a single positive variation result obtained in a single sample; and (C) 4 (4.39%) had variations of BCR-ABL transcripts in at least two consecutive samples. Of the 34 patients who had elevated levels of transcripts (group B and C), 19 (55.8%) had a < 1% of BCR-ABL/BCR ratio, 13 (38.2%) patients had a 1% to 10% increase and 2 patients had a >10% increase of RT-qPCR. The last two patients had lost a CCyR, and none of them showed mutations in the ABL gene. Transient cytogenetic alterations in Ph-negative cells were observed in five (5.5%) patients, and none of whom lost CCyR. Conclusions Despite an increase levels of BCR-ABL/BCR ratio variations by RT-qPCR, the majority of CML patients with MMR remained in CCyR. Thus, such single variations should neither be considered predictive of subsequent failure and nor an indication for altering imatinib dose or switching to second generation therapy. Changing of imatinib on the basis of BCR-ABL/BCR% sustained increase and mutational studies is a prudent approach for preserving other therapeutic options in imatinib-resistant patients.