940 resultados para Non-invasive method


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A seletividade espacial para cor tem sido investigada usando métodos eletrofisiológicos invasivos e não invasivos, e métodos psicofísicos. Em eletrofisiologia cortical visual não invasiva este tópico foi investigado usando métodos convencionais de estimulação periódica e extração de respostas por promediação simples. Novos métodos de estimulação (apresentação pseudo-aleatória) e extração de respostas corticais não invasivas (correlação cruzada) foram desenvolvidos e ainda não foram usados para investigar a seletividade espacial de cor de respostas corticais. Este trabalho objetivou introduzir esse novo método de eletrofisiologia pseudoaleatória para estudar a seletividade espacial de cor. Foram avaliados 14 tricromatas e 16 discromatópsicos com acuidade visual normal ou corrigida. Os voluntários foram avaliados pelo anomaloscópio HMC e teste de figuras de Ishihara para caracterizar a visão de cores quanto à presença de tricromacia. Foram usadas redes senoidais, 8º de ângulo visual, vermelho-verde para 8 frequências espaciais entre 0,2 a 10 cpg. O estímulo foi temporalmente modulado por uma sequência-m binária em um modo de apresentação de padrão reverso. O sistema VERIS foi usado para extrair o primeiro e o segundo slice do kernel de segunda ordem (K2.1 e K2.2, respectivamente). Após a modelagem da resposta às frequências espaciais com função de diferença de gaussianas, extraiu-se a frequência espacial ótima e banda de frequências com amplitudes acima de ¾ da amplitude máxima da função para servirem como indicadores da seletividade espacial da função. Também foi estimada a acuidade visual cromática pelo ajuste de uma função linear aos dados de amplitude a partir da frequência espacial do pico de amplitude até a mais alta frequência espacial testada. Em tricromatas, foi encontrada respostas cromáticas no K2.1 e no K2.2 que apresentaram seletividade espacial diferentes. Os componentes negativos do K2.1 e do K2.2 apresentaram sintonia passa-banda e o componente positivo do K2.1 apresentou sintonia passa-baixa. A acuidade visual estimada de todos os componentes estudados foi próxima àquelas encontradas por Mullen (1985) e Kelly (1983). Diferentes componentes celulares podem estar contribuindo para a geração do VECP pseudoaleatório. Este novo método se candidata a ser uma importante ferramenta para a avaliação não invasiva da visão de cores em humanos.

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The study of the nervous system is increasing in Veterinary Medicine. Transcranial ultrasonography (TCUS) has the advantage of being a non-invasive and low cost method compared to computerized tomography (CT) and Magnetic Resonance Imaging (MRI). The temporal bone has been used as an acoustic window in TCUS in humans. This study aimed to correlate transcranial ultrasonographic images obtained through the temporal and occipital window with healthy dog's encephalic anatomy, and to standardize the technique. 37 adult mongrel dogs were used: 30 animals in vivo, in order to perform USTC screening and seven dog corpses for brain section as well as USTC planes. Data analysis was accomplished by the non parametric Wilcoxon test. Results obtained indicate that TCUS (in dorsal and oblique planes) is a viable method for brain evaluation in dogs weighting up to 10kg without anesthesia.

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After the isolation of Helicobacter pylori from an injury at the stomach mucosa by Marshall and Wareen, work that was recognized with the Nobel Prize of Medicine or Physiology in 2005, many other works showed the relationship between the presence of H. pylori and diseases at the digestive system, such as gastritis, gastric, duodenal and peptic ulcer, and stomach cancer. The 13C-Urea Breath Test - 13C-UBT is a non-invasive diagnostic method that utilizes the breath of a patient to determine the presence of H. pylori through stable isotopes. This work aimed to find an ideal 13C-UBT Isotopic Ratio Mass Spectroscopy cut-off value (a threshold between positive and negative) to diagnose H. pylori infection at Brazilian population. Patients were selected at the UNESP-Botucatu Clinical Hospital Endoscopy Section. With these results it was possible to indicate that the best cut-off value is between 2.5 to 6 ‰ of Delta Over Baseline (DOB)

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The SPECT (Single Photon Emission Computed Tomography) systems are part of a medical image acquisition technology which has been outstanding, because the resultant images are functional images complementary to those that give anatomic information, such as X-Ray CT, presenting a high diagnostic value. These equipments acquire, in a non-invasive way, images from the interior of the human body through tomographic mapping of radioactive material administered to the patient. The SPECT systems are based on the Gamma Camera detection system, and one of them being set on a rotational gantry is enough to obtain the necessary data for a tomographic image. The images obtained from the SPECT system consist in a group of flat images that describe the radioactive distribution on the patient. The trans-axial cuts are obtained from the tomographic reconstruction techniques. There are analytic and iterative methods to obtain the tomographic reconstruction. The analytic methods are based on the Fourier Cut Theorem (FCT), while the iterative methods search for numeric solutions to solve the equations from the projections. Within the analytic methods, the filtered backprojection (FBP) method maybe is the simplest of all the tomographic reconstruction techniques. This paper's goal is to present the operation of the SPECT system, the Gamma Camera detection system, some tomographic reconstruction techniques and the requisites for the implementation of this system in a Nuclear Medicine service

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We present the results of a new, non-parametric method to reconstruct the Galactic dark matter profile directly from observations. Using the latest kinematic data to track the total gravitational potential and the observed distribution of stars and gas to set the baryonic component, we infer the dark matter contribution to the circular velocity across the Galaxy. The radial derivative of this dynamical contribution is then estimated to extract the dark matter profile. The innovative feature of our approach is that it makes no assumption on the functional form or shape of the profile, thus allowing for a clean determination with no theoretical bias. We illustrate the power of the method by constraining the spherical dark matter profile between 2.5 and 25 kpc away from the Galactic center. The results show that the proposed method, free of widely used assumptions, can already be applied to pinpoint the dark matter distribution in the Milky Way with competitive accuracy, and paves the way for future developments.

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Obesity is a risk factor in the development of several respiratory diseases. Lung volumes tend to be decreased, especially expiratory reserve volume, increasing expiratory flow limitation during tidal breathing. Barometric whole-body plethysmography is a non-invasive pulmonary function test that allows a dynamic study of breathing patterns. The objective of this study was to compare pulmonary function variables between obese and non-obese cats through the use of barometric whole-body plethysmography. Nine normal-weight and six obese cats were placed in the plethysmograph chamber, and different respiratory variables were measured. There was a significant decrease in tidal volume per kilogram (P=0.003), minute volume per kilogram (P=0.001) and peak inspiratory and expiratory flows per kilogram (P=0.001) in obese cats compared with non-obese cats. Obesity failed to demonstrate a significant increase in bronchoconstriction index variable enhanced pause (Penh), as previously reported in humans and dogs. The results show that feline obesity impairs pulmonary function in cats, although a significant increase in bronchoconstriction indexes was not observed. Non-invasive barometric whole-body plethysmography can help characterise mechanical dysfunction of the airways in obese cats.

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Obesity is the most common nutritional problem in dogs and it can cause various harmful effects on animal health. However, the effect of this condition on systolic blood pressure (SBP) in obese dogs is controversial. The indirect method of measuring PAS is the most commonly used in veterinary medicine for the diagnosis of systemic hypertension, because it is more practical and easy to access. There is little scientific information about the comparison of the two non- invasive methods of measurement of blood pressure in obese dogs. Therefore, the objective of this study was to evaluate the SBP in obese dogs by comparing both indirect methods of measuring blood pressure, with oscillometric and doppler vascular in order to verify the differences in blood pressure values, but also the best method to assess the SBP dogs in this body score condition. The study complain blood pressure measurement of 50 dogs, with were divided in obese dogs with mean body condition score (BCS) of 8.42 +/- 0.50 (n = 25) and dogs with ideal BCS of 4.56 +/- 0.51 (n = 25). At comparison of blood pressure values, SBP values obtained by doppler method (152 +/- 16mmHg) were higher than the oscillometric (136 +/- 11mmHg). Correspondence analysis determined by multivariate statistical analysis showed correlation between body condition and the procedure of the SBP. These findings suggest that the indirect method doppler can better reflect the SBP in obese dogs.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Sonohysterography was firstly described three decades ago. The saline solution infusion into the uterine cavity favors its use and provides excellent visualization of the anatomy and the inner cavity of the uterus better than the conventional transvaginal sonography To check the current role of sonohysterography in the uterine cavity assessment in women with abnormal uterine bleeding and asymptomatic, a literature review comparing sonohysterograph with conventional transvaginal sonography and/or ambulatory diagnostic hysteroscopy was carried out. To this end, relevant studies were researched in electronic databases Medline/PubMed, SciELO/LILACS. The sonohysterography is an ambulatory procedure, non-invasive, better cost-benefit, better sensitivity and specificity to identify uterine abnormalities, causing minimal discomfort and low complications rate. It was subject to revision which there is no more doubt about its accuracy. It can be concluded that the sonohysterography is a useful tool in the propedeutics to assess uterine cavity of symptomatic patients with abnormal uterine bleeding, infertility, recurrent miscarriages, and embryonic implantation failures in assisted reproduction treatment / in vitro fertilization and in any other intra and extra uterine cavity alteration. Hence, conventional transvaginal sonography is indicated as an initial method of assessment of the uterine cavity previously to ambulatory diagnostic hysteroscopy.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Background: The analysis of exhaled breath condensate (EBC) is a non-invasive technique that enables the determination of several volatile and nonvolatile substances produced in the respiratory tract, whose measurement may be useful for the diagnosis and monitoring of several respiratory diseases. Objective: The aim of this study was to produce a low-cost reusable device in order to sample exhaled breath condensate in healthy adult volunteers, and to determine the concentration of nitric oxide in the sample collected. Material and methods: The apparatus was made with a U-shaped tube of borosilicate glass. The tube was placed in a container with ice, and unidirectional respiratory valves were fitted to the distal end. Afterwards, nitric oxide was measured in the exhaled breath condensate (EBC) by chemiluminescence. Results: The total cost of the device was $120.20. EBC samples were obtained from 116 volunteers of both sexes, aged between 20 and 70. The mean volume of exhaled breath condensate collected during 10 minutes was 1.0 +/- 0.6 mL, and the mean level of nitric oxide was 12.99 +/- 14.38 mu M (median 8.72 mu M). There was no correlation between the nitric oxide levels in the exhaled breath condensate and age or gender. Conclusion: We demonstrate that it is possible to fabricate a low-cost, efficient, reusable device in order to collect and determine nitric oxide levels in EBC. We have identified no correlation between the nitric oxide levels present in the EBC obtained with this method with either age or sex. (C) 2011 SEPAR. Published by Elsevier Espana, S.L. All rights reserved.

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Faeces provide relevant biological information which includes, with the application of genetic techniques, the sex and identity of individuals that defecated, thus providing potentially useful data on the behaviour and ecology of individuals, as well as the dynamics and structure of populations. This paper presents estimates of the sex ratio of different felid species (jaguar, Panthera onca; puma, Puma concolor; and ocelot/margay, Leopardus pardalis/Leopardus wiedi) as observed in field collected faeces, and proposes several hypotheses that could explain the strikingly high proportion of faeces from male jaguars. The proportion of male and female faeces was estimated using a non-invasive faecal sampling method in 14 study areas in Mexico and Brazil. Faecal samples were genetically analysed to identify the species, the sex and the individual (the latter only for samples identified as belonging to jaguars). Considering the three species, 72.6% of faeces (n = 493) were from males; however, there were significant differences among them, with the proportion from males being higher for jaguars than for pumas and ocelots/margays. A male-bias was consistently observed in all study areas for jaguar faeces, but not for the other species. For jaguars the trend was the same when considering the number of individuals identified (n = 68), with an average of 4.2 +/- 0.56 faeces per male and 2.0 +/- 0.36 per female. The observed faecal marking patterns might be related to the behaviour of female jaguars directed toward protecting litters from males, and in both male and female pumas, to prevent interspecific aggressions from male jaguars. The hypothesis that there are effectively more males than females in jaguar populations cannot be discarded, which could be due to the fact that females are territorial and males are not, or a tendency for males to disperse into suboptimal areas for the species.

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Aims and objectives. To evaluate the effectiveness of a low-level laser therapy for pain relief in the perineum following episiotomy during childbirth. Background. Laser irradiation is a painless and non-invasive therapy for perineal pain treatment and its effects have been investigated in several studies, with no clear conclusion on its effectiveness. Design. A double-blind randomised controlled clinical trial. Method. One hundred and fourteen women who underwent right mediolateral episiotomies during vaginal birth in an in-hospital birthing centre in Sao Paulo, Brazil and reported pain =3 on a numeric scale (010) were randomised into three groups of 38 women each: two experimental groups (treated with red and infrared laser) and a control group. The experimental groups were treated with laser applied at three points directly on the episiotomy after suturing in a single session between 656 hours postpartum. We used a diode laser with wavelengths of 660 nm (red laser) and 780 nm (infrared laser). The control group participants underwent all laser procedures, excluding the emission of irradiation. The participants and the pain scores evaluator were blinded to the type of intervention. The perineal pain scores were assessed at three time points: before, immediately after and 30 minutes after low-level laser therapy. Results. The comparison of perineal pain between the three groups showed no significant differences in the three evaluations (p = 0.445), indicating that the results obtained in the groups treated with low-level laser therapy were equivalent to the control group. Conclusions. Low-level laser therapy did not decrease the intensity of perineal pain reported by women who underwent right mediolateral episiotomy. Relevance to clinical practice. The effect of laser in perineal pain relief was not demonstrated in this study. The dosage may not have been sufficient to provide relief from perineal pain after episiotomy during a vaginal birth.

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Abstract Background Double-chambered right ventricle is a rare congenital disease frequently misdiagnosed in the adult patient. An anomalous muscle band divides the right ventricle in two cavities causing variable degree of obstruction. Although echocardiography is considered a useful method for the diagnosis of this pathology in children, it has been recognized the transthoracic scanning limitation in adults. Case presentation A 29 year-old patient with double-chambered right ventricle presenting mild exercise intolerance referred for follow up of a known ventricular septal defect in whom a complete diagnosis was obtained based only on transthoracic two dimensional echocardiography without the needing of cardiac catheterization. Conclusion Based on non invasive echocardiographic diagnosis, patient was referred to surgical correction, which was completely successful.