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1.
Med Biol Eng Comput ; 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38849699

RESUMO

The common black box nature of machine learning models is an obstacle to their application in health care context. Their widespread application is limited by a significant "lack of trust." So, the main goal of this work is the development of an evaluation approach that can assess, simultaneously, trust and performance. Trust assessment is based on (i) model robustness (stability assessment), (ii) confidence (95% CI of geometric mean), and (iii) interpretability (comparison of respective features ranking with clinical evidence). Performance is assessed through geometric mean. For validation, in patients' stratification in cardiovascular risk assessment, a Portuguese dataset (N=1544) was applied. Five different models were compared: (i) GRACE score, the most common risk assessment tool in Portugal for patients with acute coronary syndrome; (ii) logistic regression; (iii) Naïve Bayes; (iv) decision trees; and (v) rule-based approach, previously developed by this team. The obtained results confirm that the simultaneous assessment of trust and performance can be successfully implemented. The rule-based approach seems to have potential for clinical application. It provides a high level of trust in the respective operation while outperformed the GRACE model's performance, enhancing the required physicians' acceptance. This may increase the possibility to effectively aid the clinical decision.

2.
Sensors (Basel) ; 20(11)2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32512850

RESUMO

A cost-effective optical instrument for continuous in-situ monitoring applications is presented. With a production cost in raw materials of 38 €, a power consumption of 300 A in sleep mode and 100 mA in active mode (5 ms reading), and a capacity to monitor turbidity and sedimentary displacement at eight different depths in the water column, the sensor was developed for sediment monitoring in coastal areas. Due to the extent and dynamics of the processes involved in these areas, observations require a wide spatial and temporal resolution. Each of the eight monitoring nodes uses one infrared backscatter channel, to estimate turbidity and sediment concentration, and one ultraviolet with one infrared transmitted light channels to distinguish organic/inorganic composition of the suspended material load. An in-lab calibration was conducted, using formazine to correlate turbidity with the electronic outputs of the instrument. An analysis of the influence of external light sources and correction techniques were performed. Moreover, an in-lab experiment was conducted to study the behaviour of the sensor-to-sediment transport, wash load and sediment accumulation. The device was deployed, with a water level sensor, in an estuarine area with high sediment dynamics. The monitoring data were analysed, showing the potential of the device to continuously monitor turbidity, sediment processes, and distinguish between organic and inorganic matter, at the different depths in the water column.

3.
Sensors (Basel) ; 19(20)2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31614983

RESUMO

A cost-effective optical sensor for continuous in-situ monitoring of turbidity and suspended particulate matter concentration (SPM), with a production cost in raw materials less than 20 €, is presented for marine or fluvial applications. The sensor uses an infrared LED and three photodetectors with three different positions related to the light source-135º, 90º and 0º-resulting in three different types of light detection: backscattering, nephelometry and transmitted light, respectively. This design allows monitoring in any type of environment, offering a wide dynamic range and accuracy for low and high turbidity or SPM values. An ultraviolet emitter-receiver pair is also used to differentiate organic and inorganic matter through the differences in absorption at different wavelengths. The optical transducers are built in a watertight structure with a radial configuration where a printed circuit board with the electronic signal coupling is assembled. An in-lab calibration of the sensor was made to establish a relation between suspended particulate matter (SPM) or the turbidity (NTU) to the photodetectors' electrical output value in Volts. Two different sizes of seashore sand were used (180 µm and 350 µm) to evaluate the particle size susceptibility. The sensor was tested in a fluvial environment to evaluate SPM change during sediment transport caused by rain, and a real test of 22 days continuous in-situ monitoring was realized to evaluate its performance in a tidal area. The monitoring results were analysed, showing the SPM change during tidal cycles as well as the influence of the external light and biofouling problems.

5.
Toxicol Appl Pharmacol ; 342: 14-21, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29407772

RESUMO

The safety profile of the ingredients used in topical dosage forms and its evaluation is an issue of utmost importance. A suitable equilibrium between safety and efficacy is crucial before promoting a dermatological product. The aim of this work was to assess the safety and biological effects of starch-based vehicles (St-BV) used in such products. The hazard, exposure and dose-response assessment were used to characterize the risk of each ingredient. The EpiSkin™ assay and human repeat insult patch tests were performed to compare the theoretical safety assessment to in vitro and in vivo data. The efficacy of the St-BV was studied using biophysical measurements in human volunteers during 28 days, showing that all ingredients and their combinations were safe for the consumer. Tissue viability determined using the EpiSkin™ testing reached values between 84.0 ±â€¯5.0% and 98.0 ±â€¯8.6% after application of St-BV, which were considered as non-irritant to the skin. These observations were confirmed by the in vivo studies where the St-BV did not induce any sensitization on the volunteers, being safe for human use. Moreover, St-BV increased skin hydration and microcirculation, emerging as an attractive alternative to chemical raw materials.


Assuntos
Alumínio/toxicidade , Cosméticos/toxicidade , Nanocápsulas/toxicidade , Pele/efeitos dos fármacos , Amido/toxicidade , Succinatos/toxicidade , Qualidade de Produtos para o Consumidor , Emulsões , Humanos , Microcirculação/efeitos dos fármacos , Testes do Emplastro , Medição de Risco , Pele/irrigação sanguínea , Pele/metabolismo , Testes de Toxicidade , Água/metabolismo
6.
J Eur CME ; 6(1): 1337478, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29644134

RESUMO

Objective: This international needs assessment was mandated by the European Society of Cardiology (ESC) to obtain an in-depth understanding of the current gaps and challenges of European cardiology professionals, with the aim to provide evidence for the development of needs-driven educational and professional development activities. Methods: This ethics-approved needs assessment was conducted among cardiologists from all sub-specialties across 56 countries of Europe and the Mediterranean basin. A mixed-methods research approach was used, combining qualitative in-depth interviews and focus groups with a quantitative survey. Results: Seventy-four (74) cardiologists participated in the qualitative phase and 866 completed the survey. Respondents represented 52 of the 56 targeted countries. Three themes were identified: 1) Challenges in the clinical decision-making process, 2) Challenges in establishing the patient-physician relationship, and 3) Sub-optimal team communication and collaboration. Specific gaps and causalities related to each challenge were found. Although most of the gaps were common across countries and sub-specialties, some significant differences were noted. Conclusion: The findings of this needs assessment indicate gaps and challenges in clinical practice across countries and across sub-specialities. Taking cardiology as an example, this study identifies clear areas of focus, especially around issues of collaboration and communication, for targeted competency-based education in Europe.

7.
Curr Microbiol ; 71(4): 449-57, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26169111

RESUMO

Cryptococcosis caused by the fungus Cryptococcus neoformans is an opportunistic mycosis, infecting mainly immunodepressed individuals. Molecular epidemiology studies of cryptococcosis in Europe are limited. This paper presents a retrospective study of cryptococcosis in 105 cryptococcal isolates from two hospitals in Lisbon, Portugal, among HIV/AIDS patients, from 1991 to 2007. Among these patients, the number of cases of cryptococcosis increased from 5.1 to 6.9 cases per year from the pre- to post-highly active antiretroviral therapy (HAART) era. As expected, the median age of the patients increased, from 32 (mean: 33 ± 8) to 39 (mean: 41 ± 10) years, and the ratio of male to female patients remained high (7.7 and 7.6, respectively). Strain genotyping based on restriction fragment length polymorphism of the orotidine monophosphate pyrophosphorylase (URA5-RFLP) gene showed that, in general, the relative frequencies of the genotypes VNI-IV are similar to those from other European countries. These frequencies were, respectively, for the pre- and post-HAART periods: 41.7 and 43.5 % for VNI; 2.8 and 17.4 % for VNII; 38.9 and 30.4 % for VNIII; 16.7 and 7.2 % for VNIV and 0 and 1.4 % for VGII. Some apparent although statistically insignificant differences among these values were observed between both periods. The genotypic frequencies were not also statistically different according to the patients' gender or age range. Of note are the high proportion of VNIII isolates (common in Europe) and the high increase in the frequency of the VNII genotype in the post-HAART. Ultimately, these results may have implications in disease therapy, management and control.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Criptococose/epidemiologia , Cryptococcus neoformans/classificação , Infecções por HIV/complicações , Orotato Fosforribosiltransferase/genética , Polimorfismo de Fragmento de Restrição , Infecções Oportunistas Relacionadas com a AIDS/microbiologia , Adulto , Criptococose/microbiologia , Cryptococcus neoformans/genética , Cryptococcus neoformans/isolamento & purificação , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Portugal/epidemiologia , Estudos Retrospectivos
8.
Genet Mol Res ; 13(3): 5221-40, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-25061747

RESUMO

In Brazil, the first genetically modified (GM) crop was released in 1998, and it is estimated that 84, 78, and 50% of crop areas containing soybean, corn, and cotton, respectively, were transgenic in 2012. This intense and rapid adoption rate confirms that the choice to use technology has been the main factor in developing national agriculture. Thus, this review focuses on understanding these dynamics in the context of farmers, trade relations, and legislation. To accomplish this goal, a survey was conducted using the database of the National Cultivar Registry and the National Service for Plant Variety Protection of the Ministry of Agriculture, Livestock and Supply [Ministério da Agricultura, Pecuária e Abastecimento (MAPA)] between 1998 and October 13, 2013. To date, 36 events have been released: five for soybeans, 18 for corn, 12 for cotton, and one for beans. From these events, 1395 cultivars have been developed and registered: 582 for soybean, 783 for corn and 30 for cotton. Monsanto owns 73.05% of the technologies used to develop these cultivars, while the Dow AgroScience - DuPont partnership and Syngenta have 16.34 and 4.37% ownership, respectively. Thus, the provision of transgenic seeds by these companies is an oligopoly supported by legislation. Moreover, there has been a rapid replacement of conventional crops by GM crops, whose technologies belong almost exclusively to four multinational companies, with the major ownership by Monsanto. These results reflect a warning to the government of the increased dependence on multinational corporations for key agricultural commodities.


Assuntos
Agricultura/legislação & jurisprudência , Produtos Agrícolas/provisão & distribuição , Plantas Geneticamente Modificadas , Agricultura/economia , Agricultura/ética , Brasil , Produtos Agrícolas/economia , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Gossypium/genética , Gossypium/crescimento & desenvolvimento , Humanos , Glycine max/genética , Glycine max/crescimento & desenvolvimento , Glycine max/provisão & distribuição , Transgenes , Zea mays/genética , Zea mays/crescimento & desenvolvimento , Zea mays/provisão & distribuição
9.
Value Health ; 17(7): A540, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27201737
11.
Genet Mol Res ; 12(2): 2109-19, 2013 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-23913390

RESUMO

The objective of this study was to determine the optimal number of repetitions to be used in competition trials of popcorn traits related to production and quality, including grain yield and expansion capacity. The experiments were conducted in 3 environments representative of the north and northwest regions of the State of Rio de Janeiro with 10 Brazilian genotypes of popcorn, consisting by 4 commercial hybrids (IAC 112, IAC 125, Zélia, and Jade), 4 improved varieties (BRS Ângela, UFVM-2 Barão de Viçosa, Beija-flor, and Viçosa) and 2 experimental populations (UNB2U-C3 and UNB2U-C4). The experimental design utilized was a randomized complete block design with 7 repetitions. The Bootstrap method was employed to obtain samples of all of the possible combinations within the 7 blocks. Subsequently, the confidence intervals of the parameters of interest were calculated for all simulated data sets. The optimal number of repetition for all of the traits was considered when all of the estimates of the parameters in question were encountered within the confidence interval. The estimates of the number of repetitions varied according to the parameter estimated, variable evaluated, and environment cultivated, ranging from 2 to 7. It is believed that only the expansion capacity traits in the Colégio Agrícola environment (for residual variance and coefficient of variation), and number of ears per plot, in the Itaocara environment (for coefficient of variation) needed 7 repetitions to fall within the confidence interval. Thus, for the 3 studies conducted, we can conclude that 6 repetitions are optimal for obtaining high experimental precision.


Assuntos
Algoritmos , Cruzamento , Cruzamentos Genéticos , Zea mays/economia , Brasil , Cruzamento/economia , Intervalos de Confiança , Genótipo , Hibridização Genética , Característica Quantitativa Herdável , Sementes/genética , Seleção Genética , Zea mays/genética
12.
Transplant Proc ; 44(8): 2413-5, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23026609

RESUMO

BACKGROUND: The identification of the psychological issues that impair the quality of life and the adherence to treatment in transplant candidates are important. OBJECTIVE: This study evaluated the presence of symptoms of depression and the quality of life of liver transplant candidates. METHODS: One hundred liver transplant candidates underwent a psychological analysis using the following instruments: the short form-36 (SF-36) quality of life questionnaire, the Beck depression inventory (BDI), and Structured Interviews for liver transplant candidates. RESULTS: Seventy-three (73%) of the patients were males. Interestingly, 63% of the patients were in a domestic partnership. At the time of the evaluation, 55 patients were not working due to illness, 27 patients were actively working, and 11 patients were retired. Importantly, fears related to the transplant (e.g., fear the surgery and of death) were identified in 38% of the patients. The data from this study demonstrated a significant negative correlation between depressive scores (BDI) and seven of the eight areas of quality of life (SF-36), such as functional capacity (r = .317, P = .0013), social aspects (r = -.469, P < .0001), economic aspects (r = -.319, P = .0012), and mental health (r = -.3832, P < .0001). CONCLUSION: The data indicated that the psychological aspects related to transplants require psychological intervention because they can affect the recuperation process, the quality of life, and the adherence to treatment for potential transplant patients.


Assuntos
Depressão/etiologia , Hepatopatias/cirurgia , Transplante de Fígado/psicologia , Saúde Mental , Qualidade de Vida , Listas de Espera , Adolescente , Adulto , Idoso , Atitude Frente a Morte , Efeitos Psicossociais da Doença , Depressão/diagnóstico , Depressão/psicologia , Emprego/psicologia , Medo , Feminino , Humanos , Hepatopatias/diagnóstico , Hepatopatias/mortalidade , Hepatopatias/psicologia , Transplante de Fígado/efeitos adversos , Transplante de Fígado/mortalidade , Masculino , Estado Civil , Pessoa de Meia-Idade , Cooperação do Paciente , Prognóstico , Aposentadoria/psicologia , Inquéritos e Questionários , Adulto Jovem
13.
Work ; 41 Suppl 1: 3732-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22317289

RESUMO

INTRODUCTION: Work organization patterns and working conditions experienced by nursing personnel in the hospital settings may be associated to increased morbidity among these health workers. AIM: To estimate the prevalence and factors associated with self-reported diseases among nursing personnel at the emergency hospital in Rio Branco/State of Acre, Brazil. METHODS: A cross-sectional study was conducted involving 272 participants who answered a questionnaire including sociodemographic characteristics, working conditions, lifestyles, work ability, and a fatigue perception scale. The self-reported diseases in the 12 months prior to data collection were considered the dependent variable. RESULTS: A total of 85.7% of the participants reported one or more diseases in the past 12 months. Most prevalent diseases were: musculoskeletal diseases (37.1%), digestive diseases (28.7%), mental disorders (28.3%), work injuries (27.9%), and respiratory diseases (26.8%). The following significant variables remained in the final model: high work demands (OR 2.69), reported fatigue (OR 3.59), night work (OR 6.55) and being a technician or nursing assistant (OR 4.23). CONCLUSIONS: Variables related to working conditions and work organization were associated with the occurrence of reported diseases among nursing professionals. Health promotion measures at work require a comprehensive approach including the working conditions and the work organization.


Assuntos
Doenças do Sistema Digestório/epidemiologia , Transtornos Mentais/epidemiologia , Doenças Musculoesqueléticas/epidemiologia , Enfermagem , Doenças Profissionais/epidemiologia , Traumatismos Ocupacionais/epidemiologia , Doenças Respiratórias/epidemiologia , Adulto , Brasil/epidemiologia , Estudos Transversais , Fadiga/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Tolerância ao Trabalho Programado , Carga de Trabalho , Local de Trabalho/organização & administração , Local de Trabalho/psicologia , Adulto Jovem
14.
Genet Mol Res ; 10(2): 792-809, 2011 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-21563073

RESUMO

During the last 20 years, the national production of grains has increased 156.1%; productivity increased 93.8% and there has been an increase of 29.1% in cultivated area. Currently, agribusiness is responsible for 40% of Brazilian exports. Nevertheless, there is little quantitative information on the main plant species of economic interest that have been registered and protected in the Agriculture, Fisheries and Food Supply Ministry (MAPA) by public and private companies, as well as by public-private partnerships. Consequently, we investigated the registry and protection of 27 species of economic interest, including the 15 that are the basis of the Brazilian diet, based on the information available on the site CultivarWeb, of MAPA, for the period from 1998 to August 30, 2010. We also examined the legislation that regulates registration and protection procedures and its implications for plant breeding and plant product development. It was found that the private sector controls 73.1% of the registrations and 53.56% of the protections, while 10.73% of the protections were of material developed overseas. Public-private partnerships contributed little to the development of new cultivars, with 0.5% of the registries and 3.61% of the protections. We conclude that plant protection directed private investment to development of wheat and rice varieties, with the greatest public investments directed to corn and sorghum. After the Cultivar Protection Law was implemented, there was restriction of access to germplasm banks, which could inhibit advances in Brazilian plant breeding programs, indicating a need for revision of this legal barrier.


Assuntos
Cruzamento/economia , Cruzamento/legislação & jurisprudência , Produtos Agrícolas/economia , Abastecimento de Alimentos/economia , Abastecimento de Alimentos/legislação & jurisprudência , Agricultura , Brasil , Bases de Dados Factuais , Indústrias/economia , Indústrias/legislação & jurisprudência , Oryza , Setor Privado , Parcerias Público-Privadas , Sorghum , Triticum , Zea mays
15.
Toxicon ; 56(6): 980-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20621114

RESUMO

Species of the genus Bothrops induce the vast majority of snakebite envenomings in Latin America. A preclinical study was performed in the context of a regional network of public laboratories involved in the production, quality control and development of antivenoms in Latin America. The ability of seven polyspecific antivenoms, produced in Argentina, Brazil, Peru, Bolivia, Colombia and Costa Rica, to neutralize lethal, hemorrhagic, coagulant, defibrinogenating and myotoxic activities of the venoms of Bothrops neuwiedi (diporus) (Argentina), Bothrops jararaca (Brazil), B. neuwiedi (mattogrossensis) (Bolivia), Bothrops atrox (Peru and Colombia) and Bothrops asper (Costa Rica) was assessed using standard laboratory tests. Despite differences in the venom mixtures used in the immunization of animals for the production of these antivenoms, a pattern of extensive cross-neutralization was observed between these antivenoms and all the venoms tested, with quantitative differences in the values of effective doses. This study reveals the capacity of these antivenoms to neutralize, in preclinical tests, homologous and heterologous Bothrops venoms in Central and South America, and also highlight quantitative differences in the values of Median Effective Doses (ED50s) between the various antivenoms.


Assuntos
Antivenenos/imunologia , Bothrops/fisiologia , Venenos de Crotalídeos/imunologia , Fatores Imunológicos/imunologia , Testes de Neutralização/métodos , Animais , Coagulação Sanguínea/efeitos dos fármacos , Creatina Quinase/sangue , Venenos de Crotalídeos/efeitos adversos , Avaliação Pré-Clínica de Medicamentos , Feminino , Fibrinólise/efeitos dos fármacos , Hemorragia/induzido quimicamente , América Latina , Dose Letal Mediana , Masculino , Camundongos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/enzimologia , Miosite/induzido quimicamente
16.
Ultrasound Obstet Gynecol ; 34(6): 673-7, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19859908

RESUMO

OBJECTIVES: The main goal was to develop a reproducible method for estimating the diffusion of water in human fetal lung tissue using diffusion-weighted imaging (DWI). A secondary objective was to determine the relationship of the apparent diffusion coefficients (ADCs) in the fetal lung to menstrual age and total lung volume. METHODS: Normal pregnant volunteers were scanned on a 1.5-Tesla (T) magnetic resonance imaging (MRI) system. The MRI system was equipped with 40-mT/m gradients (slew rate 200 T/m/s, rise time 0.2 ms). A six-channel body array coil was used for signal reception. Single-shot DWI utilized TE/TR 125/3400 ms, slice thickness 4 mm, field of view 280 mm x 280 mm, interslice gap 0.8 mm and a matrix of 128 x 128. The voxel size was 2.5 mm x 2.5 mm x 4.0 mm. Two b-values (0 and 1000) were chosen along three orthogonal directions. ADC maps were created using assigned b-values. Simple linear regression was performed with Pearson correlation coefficient. Interexaminer and intraexaminer bias, and 95% limits of agreement (LOA) were determined using Bland-Altman plots. RESULTS: Forty-seven scans were performed at a mean +/- SD of 29.2 +/- 4.5 weeks. The median coefficient of variation for ADC was 5.6% (interquartile range, 4.0-8.1%). No differences in ADC values were found between right and left lungs. Normally distributed ADC measurements were not significantly correlated with either total lung volume (r(2) = 0.0001, P = 0.94) or menstrual age (r(2) = 0.003, P = 0.70). The mean ADC value was 1.75 (95% CI, 1.63-1.86). Mean +/- SD intraexaminer bias was -0.15 +/- 2.3 (95% LOA, -4.7 to + 4.4) and interexaminer bias was 2.2 +/- 3.5 (95% LOA, -4.7 to + 9.1). CONCLUSIONS: Our findings suggest that ADC measurements of the fetal lung are reproducible between blinded examiners and are independent of menstrual age, as well as lung volume.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Desenvolvimento Fetal/fisiologia , Pulmão/fisiologia , Adulto , Feminino , Idade Gestacional , Humanos , Pulmão/diagnóstico por imagem , Pulmão/embriologia , Gravidez , Valores de Referência , Reprodutibilidade dos Testes , Ultrassonografia
17.
Ultrasound Obstet Gynecol ; 31(5): 520-8, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18389488

RESUMO

OBJECTIVES: To develop individualized growth assessment (IGA) standards for upper (ThC(u)) and middle (ThC(m)) fetal thigh circumferences using three-dimensional ultrasonography. METHODS: A prospective, longitudinal sonographic study of 30 fetuses was performed beginning at 18 weeks' menstrual age. Second-trimester sonographic parameters were measured from three-dimensional volume data to establish IGA standards. Normal infant growth outcomes were confirmed using modified Neonatal Growth Assessment Scores (m(3)NGAS(51)). ThC(u) and ThC(m) were studied in more detail. Rossavik growth model specification procedures, based on the slopes of the second-trimester growth curves, were developed for both ThC(u) and ThC(m). Third-trimester growth trajectories and birth measurements were subsequently predicted for these parameters. Percentage deviations during the third trimester and percentage differences at actual birth age were used to compare observed and predicted measurements. The 95% ranges for Growth Potential Realization Index (GPRI) values for both types of thigh circumference were determined. Values for m(3)NGAS(51) using GPRI(ThC(u)), GPRI(ThC(m)) and GPRI(ThC(o)) (original method) were compared. RESULTS: The 30 newborns had no postnatal evidence of abnormal growth. Two examiners demonstrated a satisfactory measurement bias of mean +/- SD 2.1 +/- 3.6 (95% limits of agreement,-4.9 to 9.1)% for ThC(m) and 3.3 +/- 4.1 (95% limits of agreement,-4.8 to 11.4)% for ThC(u). Rossavik functions fitted parameter trajectories well, with mean R(2) values of 99.5 +/- 0.4% for ThC(u) and 99.6 +/- 0.3% for ThC(m). By fixing coefficients k at their mean values, their respective fits did not change, and the variabilities of coefficients c and s were significantly reduced. For ThC(u), coefficient c was significantly related to the second-trimester slope (R(2)=98.6%), as was s to c(R(2)=91.0%). For ThC(m), coefficient c was significantly related to the second-trimester slope (R(2)=98.6%), as was s to c(R(2)=85.6%). Third-trimester growth trajectories, derived from second-trimester slopes for individual fetuses, had third-trimester deviations of 0.07 +/- 3.7% for ThC(u) and-0.04 +/- 3.7% for ThC(m). Percentage differences at birth age were 16.8 +/- 10.2% for ThC(u) and 8.9 +/- 9.5% for ThC(m). With correction for systematic overestimations, the mean GPRI values were 103.7 (95% range, 90-121)% for ThC(u) and 101.6 (95% range, 88-118)% for ThC(m). Corresponding mean +/- SD m(3)NGAS(51) values, using GPRI(ThC(u)), GPRI(ThC(m)) and GPRI(ThC(o)), were 203 +/- 11%, 201 +/- 10% and 200 +/- 9%, respectively. CONCLUSIONS: Fetal thigh circumference can be measured reliably and evaluated using standard IGA methods. Both ThC(u) and ThC(m) give similar results in the third trimester but neonatal thigh circumference predictions are improved by using ThC(m). Corresponding GPRI(ThC(m)) values are closer to the ideal value of 100% and can be used in m(3)NGAS(51) calculations for assessment of neonatal growth outcome.


Assuntos
Fêmur/embriologia , Desenvolvimento Fetal/fisiologia , Imageamento Tridimensional/métodos , Ultrassonografia Pré-Natal/métodos , Adulto , Feminino , Fêmur/diagnóstico por imagem , Humanos , Recém-Nascido , Estudos Longitudinais , Masculino , Gravidez , Trimestres da Gravidez , Estudos Prospectivos
18.
Ultrasound Obstet Gynecol ; 28(3): 255-60, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16937412

RESUMO

OBJECTIVE: Our main objective was to determine the value of three-dimensional ultrasonography (3DUS) and Virtual Organ Computer-aided AnaLysis (VOCAL) in the evaluation of gestational sac volume and morphology during early pregnancy. METHODS: Twenty-eight normal early pregnancies were scanned approximately every 2 weeks using transabdominal (TAS) and transvaginal (TVS) sonography. The VOCAL technique was used to create computerized surface models to classify gestational sac shapes as discoid or ellipsoid. Serial sac volume changes were analyzed using repeated measures ANOVA. Bland-Altman plots determined examiner bias and limits of agreement (LOA) for sac volume measurements. Gestational sac volumes were compared between the two-dimensional (2D) ellipsoid and VOCAL techniques. Differences between volume measurements were tested using the two-tailed paired t-test with statistical significance at the P < 0.05 level. RESULTS: Each subject was examined at a mean +/- SD menstrual age of 7.9 +/- 0.6 weeks (Scan 1), 9.9 +/- 0.6 weeks (Scan 2), and 11.9 +/- 0.6 weeks (Scan 3). Sac volumes significantly increased over time from 22 +/- 11 mL at Scan 1, to 57 +/- 21 mL at Scan 2 and 116 +/- 35 mL at Scan 3 (P < 0.001). Predominant sac shapes were classified as ellipsoid (76.2%) or discoid (23.8%). Additional descriptors included: concave (60.7%), irregular (53.6%), or smooth (7.1%), with 19% of the overall group having more than one additional shape attribute. Clinically acceptable volume measurement bias and agreement were found for the following comparisons: (1) TAS versus TVS; (2) interobserver volume measurements; and (3) intraobserver volume measurements. The VOCAL technique yielded slightly greater sac volumes (64 +/- 45.4 mL) when compared to the 2D ellipsoid model (48.6 +/- 36.8 mL) (28.9 +/- 24.3% (95% limit of agreement range, - 18.7 to 76.5%), P < 0.001). CONCLUSIONS: Reproducible sac volume measurements can be obtained using VOCAL with either TAS or TVS. Early gestational sacs variably appear as discoid or ellipsoid structures with a concave indentation from the placenta. Sac volumes can be underestimated if an ellipsoid shape is assumed. Morphological and quantitative analysis of the gestational sac may provide baseline parameters for studying patients at risk for early pregnancy failure.


Assuntos
Membranas Extraembrionárias/diagnóstico por imagem , Ultrassonografia Pré-Natal/métodos , Análise de Variância , Desenvolvimento Embrionário/fisiologia , Membranas Extraembrionárias/crescimento & desenvolvimento , Feminino , Idade Gestacional , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Valor Preditivo dos Testes , Gravidez , Primeiro Trimestre da Gravidez , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Ultrasound Obstet Gynecol ; 24(7): 766-74, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15586365

RESUMO

OBJECTIVES: The main goals of this study were to introduce fractional thigh volume (TVol) as a new soft tissue parameter for fetal growth evaluation, define its relationship to menstrual age, and develop individualized fetal growth standards based on Rossavik growth models. METHODS: A prospective, longitudinal study of 22 fetuses was conducted with conventional biometry and TVol measurements by three-dimensional ultrasonography. Infant growth outcomes were determined from modified neonatal growth assessment scores. Rossavik functions (P = c(t)k+s(t)) were used to fit complete datasets to examine relationships between TVol and model coefficients. Second-trimester models were subsequently specified from the linear slopes of growth curves before 28.0 menstrual weeks with each fetus acting as its own control. Third-trimester trajectories and birth measurements were predicted for standard growth parameters and TVol. Observed and predicted measurements were compared using percent deviations and growth potential realization index values. Four additional infants, with serial prenatal scans and postnatal evidence of intrauterine growth restriction (IUGR), were also evaluated. RESULTS: All 22 fetuses had no evidence of growth abnormalities after delivery. Accelerated soft tissue deposition occurred in the fetal thigh by 28 menstrual weeks. A mean TVol start point of 9.0 +/- 1.4 menstrual weeks was consistent with embryological studies of thigh development. Rossavik functions fitted all TVol trajectories well (mean R2 = 0.998 +/- 0.002). By fixing the coefficient k at its mean value (2.976), the fit did not change and the variabilities of coefficients c and s were reduced. The mean percent deviation between observed and predicted third-trimester TVol measurements was -0.048 +/- 7.5%. Relatively early pathological deviations were observed for TVol in all four fetuses with IUGR; in these cases the abdominal circumference was abnormal in only one fetus and thigh circumference in none. CONCLUSIONS: Individualized growth assessment can be used to accurately predict TVol during the third trimester of pregnancy and at birth. Expected growth trajectories, from second-trimester data, do not rely on population-based standards because each fetus serves as its own control. This new parameter may allow earlier detection and improved monitoring of fetal soft tissue abnormalities such as IUGR.


Assuntos
Retardo do Crescimento Fetal/diagnóstico por imagem , Imageamento Tridimensional , Coxa da Perna/diagnóstico por imagem , Ultrassonografia Pré-Natal , Feminino , Desenvolvimento Fetal/fisiologia , Idade Gestacional , Humanos , Modelos Lineares , Gravidez , Estudos Prospectivos , Coxa da Perna/embriologia
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