998 resultados para Multivariate Comparison
Resumo:
It is not well established whether cytokine production differs in response to different clinical forms of visceral leishmaniasis (VL). In this work, we performed a cross-sectional study to investigate the plasma levels of cytokines [interferon (IFN)-γ, tumour necrosis factor (TNF)-α, interleukin (IL)-2, IL-4, IL-10 and IL-12] involved in the pathogenesis of VL in 80 subjects from VL endemic areas, including subjects with active VL, subjects with asymptomatic infection, subjects with cured VL and uninfected controls. The patients were recruited by sampling from a referral hospital and by random selection from a population-based cohort study. The results showed significant differences in the plasma concentration of all cytokines between the groups (p < 0.05). Patients with the active disease had higher plasma levels of IL-10, IL-4, INF-γ and TNF-α relative to the other groups and they produced more IL-12 than asymptomatic and cured subjects. Only the IL-2 concentration was higher in the asymptomatic and cured subjects relative to the patients with active disease (p < 0.05). Our results suggest that these cytokines can be used as markers in epidemiological studies conducted in endemic areas to distinguish between different clinical forms of VL. However, their usefulness should be confirmed in investigations conducted in other endemic areas.
Resumo:
OBJECTIVE: Previous literature has suggested that laws and regulations may impact the use of palliative sedation. Our present study compares the attitudes of French-speaking physicians practicing in the Quebec and Swiss environments, where different laws are in place regarding physician-assisted suicide. METHOD: Data were drawn from two prior studies, one by Blondeau and colleagues and another by Beauverd and coworkers, employing the same two-by-two experimental design with length of prognosis and type of suffering as independent variables. Both the effect of these variables and the effect of their interaction on Swiss and Quebec physicians' attitudes toward sedation were compared. The written comments of respondents were submitted to a qualitative content analysis and summarized in a comparative perspective. RESULTS: The analysis of variance showed that only the type of suffering had an effect on physicians' attitudes toward sedation. The results of the Wilcoxon test indicated that the attitudes of physicians from Quebec and Switzerland tended to be different for two vignettes: long-term prognosis with existential suffering (p = 0.0577) and short-term prognosis with physical suffering (p = 0.0914). In both cases, the Swiss physicians were less prone to palliative sedation. SIGNIFICANCE OF RESULTS: The attitudes of physicians from Quebec and Switzerland toward palliative sedation, particularly regarding prognosis and type of suffering, seem similar. However, the results suggest that physicians from Quebec could be slightly more open to palliative sedation, even though most were not in favor of this practice as an answer to end-of-life existential suffering.
Resumo:
A vaccination campaign against pandemic influenza A (H1N1)pdm09 was held in Brazil in March 2010, using two types of monovalent split virus vaccines: an AS03-adjuvanted vaccine and a non-adjuvanted vaccine. We compared the reactogenicity of the vaccines in health professionals from a Clinical Research Institute in Rio de Janeiro, Brazil and there were no serious adverse events following immunization (AEFI) among the 494 subjects evaluated. The prevalence of any AEFI was higher in the AS03-adjuvanted vaccine at 2 h and 24 h post-vaccination [preva-lence ratio (PR): 2.05, confidence interval (CI) 95%: 1.55-2.71, PR: 3.42, CI 95%: 2.62-4.48, respectively]; however, there was no difference between the vaccines in the assessments conducted at seven and 21 days post-vaccination. The group receiving the AS03 post-adjuvanted vaccine had a higher frequency of local reactions at 2 h (PR: 3.01, CI 95%: 2.12-4.29), 24 h (PR: 4.57, CI 95%: 3.29-6.37) and seven days (PR: 6.05, CI 95%: 2.98-12.28) post-vaccination. We concluded that the two types of vaccines caused no serious AEFI in the studied population and the adjuvanted vaccine was more reactogenic, particularly in the 24 h following vaccination. This behaviour must be confirmed and better characterised by longitudinal studies in the general population.
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Contact surveillance is an important strategy to ensure effective early diagnosis and control of leprosy; passive detection may not be as efficient because it is directly tied to the ready availability of heath care services and health education campaigns. The aim of this study was to reinforce that contact surveillance is the most effective strategy for the control of leprosy. The analysed data were obtained from a cohort of contacts and cases diagnosed through a national referral service for leprosy. We analysed data from patients diagnosed between 1987-2010 at the Souza Araújo Ambulatory in Rio de Janeiro. Epidemiological characteristics of leprosy cases diagnosed through contact surveillance and characteristics of passively detected index cases were compared using a conditional logistic regression model. Cases diagnosed by contact surveillance were found earlier in the progression of the disease, resulting in less severe clinical presentations, lower levels of initial and final disability grades, lower initial and final bacterial indices and a lower prevalence of disease reaction. In this respect, contact surveillance proved to be an effective tertiary prevention strategy, indicating that active surveillance is especially important in areas of high endemicity, such as Brazil.
Resumo:
The diagnosis of leprosy continues to be based on clinical symptoms and early diagnosis and treatment are critical to preventing disability and transmission. Sensitive and specific laboratory tests are not available for diagnosing leprosy. Despite the limited applicability of anti-phenolic glycolipid-I (PGL-I) serology for diagnosis, it has been suggested as an additional tool to classify leprosy patients (LPs) for treatment purposes. Two formats of rapid tests to detect anti-PGL-I antibodies [ML immunochromatography assay (ICA) and ML Flow] were compared in different groups, multibacillary patients, paucibacillary patients, household contacts and healthy controls in Brazil and Nepal. High ML Flow intra-test concordance was observed and low to moderate agreement between the results of ML ICA and ML Flow tests on the serum of LPs was observed. LPs were "seroclassified" according to the results of these tests and the seroclassification was compared to other currently used classification systems: the World Health Organization operational classification, the bacilloscopic index and the Ridley-Jopling classification. When analysing the usefulness of these tests in the operational classification of PB and MB leprosy for treatment and follow-up purposes, the ML Flow test was the best point-of-care test for subjects in Nepal and despite the need for sample dilution, the ML ICA test yielded better performance among Brazilian subjects. Our results identified possible ways to improve the performance of both tests.
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Equality with men in the world of paid work has been a major feminist objective. Given that work in the `public' sphere has historically been shaped on the assumption that the `worker' will be male, then national employment systems which facilitate masculine employment patterns (i.e. full-time work and unbroken employment careers) might be expected to be more likely to generate gender equality. This paper compares women's employment in France (where `masculine' careers for women are common) and Britain (where part-time work and broken employment careers are more likely) at the macro, meso (occupational), and micro (individual) levels. The two occupations studied are finance and pharmacy. The evidence presented suggests that there are considerable similarities between women in the two countries at the occupational and individual level, despite national variations. In the light of this evidence, structural and individual explanations of women's employment behaviour are examined, and the continuing significance of structural constraint on the patterning of gender relations is emphasised.
Resumo:
Background: Despite the increasing incidences of the publication of assessment frameworks intending to establish the "standards" of the quality of qualitative research, the research conducted using such empirical methods are still facing difficulties in being published or recognised by funding agencies. Methods: We conducted a thematic content analysis of eight frameworks from psychology/psychiatry and general medicine. The frameworks and their criteria are then compared against each other. Findings: The results illustrated the difficulties in reaching consensus on the definition of quality criteria. This showed the differences between the frameworks from the point of views of the underlying epistemology and the criteria suggested. Discussion: The aforementioned differences reflect the diversity of paradigms implicitly referred to by the authors of the frameworks, although rarely explicitly mentioned in text. We conclude that the increase in qualitative research and publications has failed to overcome the difficulties in establishing shared criteria and the great heterogeneity of concepts raises methodological and epistemological problems.
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Rabies is a neurotropic disease that is often lethal. The early diagnosis of rabies infection is important and requires methods that allow for the isolation of the virus from animals and humans. The present study compared a modified shell vial (MSV) procedure using 24-well tissue culture plates with the mouse inoculation test (MIT), which is considered the gold standard for rabies virus isolation. Thirty brain samples (25 positive and 5 negative by the fluorescent antibody test) obtained from different animal species at the National Institute of Hygiene Rafael Rangel in Caracas, Venezuela, were studied by the MIT and MSV assays. Nine samples (36%) were positive at 24 h, 10 (40%) were positive at 48 h and six (24%) were positive at 72 h by the MSV assay. With the MIT assay, 76% were positive at six days post inoculation and 12% were positive at 12 and 18 days post inoculation. One sample that was negative according to the MSV assay was positive with MIT on the 12th day. The MSV procedure exhibited a sensitivity of 96.2%, a specificity of 100%, a positive predictive value of 100% and a negative predictive value 80%. This procedure allowed for rapid rabies virus detection. MIT can be employed as an alternative method in laboratories without tissue culture facilities.
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BACKGROUND: Diffusion-weighted magnetic resonance imaging (MRI) is increasingly being used for assessing the treatment succes in oncology, but the real clinical value needs to evaluated by comparison with other, already established, metabolic imaging techniques. PURPOSE: To prospectively evaluate the clinical potential of diffusion-weighted MRI with apparent diffusion coefficient (ADC) mapping for gastrointestinal stromal tumor (GIST) response to targeted therapy compared with 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). MATERIAL AND METHODS: Eight patients (mean age, 56 ± 11 years) known to have metastatic GIST underwent 18F-FDG PET/CT and MRI (T1Gd, DWI [b = 50,300,600], ADC mapping) simultaneously, before and after change in targeted therapy. MR and PET/CT examinations were first analyzed blindly. Second, PET/CT images were co-registered with T1Gd-MR images for lesion detection. Only 18F-FDG avid lesions were considered. Maximum standardized uptake value (SUVmax) and the corresponding minimum ADCmin were measured for the six largest lesions per patient, if any, on baseline and follow-up examinations. The relationship between changes in SUVmax and ADCmin was analyzed (Spearman's correlation). RESULTS: Twenty-four metastases (12 hepatic, 12 extra-hepatic) were compared on PET/CT and MR images. SUVmax decreased from 7.7 ± 8.1 g/mL to 5.5 ± 5.4 g/mL (P = 0.20), while ADCmin increased from 1.2 ± 0.3 × 10(-3)mm(2)/s to 1.5 ± 0.3 × 10(-3)mm(2)/s (P = 0.0002). There was a significant association between changes in SUVmax and ADCmin (rho = - 0.62, P = 0.0014), but not between changes in lesions size (P = 0.40). CONCLUSION: Changes in ADCmin correlated with the response of 18F-FDG avid GIST to targeted therapy. Thus, diffusion-weighted MRI may represent a radiation-free alternative for follow-up treatment for metastatic GIST patients.
Resumo:
Trypanosoma cruzi infects humans when infected triatomine vector excreta contaminate breaks in skin or mucosal surfaces. T. cruzi insect-derived metacyclic trypomastigotes (IMT) invade through gastric mucosa after oral challenges without any visible inflammatory changes, while cutaneous and conjunctival infections result in obvious local physical signs. In this study we compared the infectivity of T. cruzi IMT in mice after cutaneous and oral contaminative challenges simulating natural infections. The 50% infective dose (ID50) for oral challenge was 100 fold lower than the ID50for cutaneous challenge, indicating that oral mucosal transmission is more efficient than cutaneous transmission.
Comparison of three commercially available radio frequency coils for human brain imaging at 3 Tesla.
Resumo:
OBJECTIVE: To evaluate a transverse electromagnetic (TEM), a circularly polarized (CP) (birdcage), and a 12-channel phased array head coil at the clinical field strength of B0 = 3T in terms of signal-to-noise ratio (SNR), signal homogeneity, and maps of the effective flip angle alpha. MATERIALS AND METHODS: SNR measurements were performed on low flip angle gradient echo images. In addition, flip angle maps were generated for alpha(nominal) = 30 degrees using the double angle method. These evaluation steps were performed on phantom and human brain data acquired with each coil. Moreover, the signal intensity variation was computed for phantom data using five different regions of interest. RESULTS: In terms of SNR, the TEM coil performs slightly better than the CP coil, but is second to the smaller 12-channel coil for human data. As expected, both the TEM and the CP coils show superior image intensity homogeneity than the 12-channel coil, and achieve larger mean effective flip angles than the combination of body and 12-channel coil with reduced radio frequency power deposition. CONCLUSION: At 3T the benefits of TEM coil design over conventional lumped element(s) coil design start to emerge, though the phased array coil retains an advantage with respect to SNR performance.
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RATIONALE AND OBJECTIVES: Recent developments of magnetic resonance imaging enabled free-breathing coronary MRA (cMRA) using steady-state-free-precession (SSFP) for endogenous contrast. The purpose of this study was a systematic comparison of SSFP cMRA with standard T2-prepared gradient-echo and spiral cMRA. METHODS: Navigator-gated free-breathing T2-prepared SSFP-, T2-prepared gradient-echo- and T2-prepared spiral cMRA was performed in 18 healthy swine (45-68 kg body-weight). Image quality was investigated subjectively and signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and vessel sharpness were compared. RESULTS: SSFP cMRA allowed for high quality cMRA during free breathing with substantial improvements in SNR, CNR and vessel sharpness when compared with standard T2-prepared gradient-echo imaging. Spiral imaging demonstrated the highest SNR while image quality score and vessel definition was best for SSFP imaging. CONCLUSION: Navigator-gated free-breathing T2-prepared SSFP cMRA is a promising new imaging approach for high signal and high contrast imaging of the coronary arteries with improved vessel border definition.
Resumo:
BACKGROUND: Straylight gives the appearance of a veil of light thrown over a person's retinal image when there is a strong light source present. We examined the reproducibility of the measurements by C-Quant, and assessed its correlation to characteristics of the eye and subjects' age. PARTICIPANTS AND METHODS: Five repeated straylight measurements were taken using the dominant eye of 45 healthy subjects (age 21-59) with a BCVA of 20/20: 14 emmetropic, 16 myopic, eight hyperopic and seven with astigmatism. We assessed the extent of reproducibility of straylight measures using the intraclass correlation coefficient. RESULTS: The mean straylight value of all measurements was 1.01 (SD 0.23, median 0.97, interquartile range 0.85-1.1). Per 10 years of age, straylight increased in average by 0.10 (95%CI 0.04 to 0.16, p < 0.01]. We found no independent association of refraction (range -5.25 dpt to +2 dpt) on straylight values (0.001; 95%CI -0.022 to 0.024, p = 0.92). Compared to emmetropic subjects, myopia reduced straylight (-.011; -0.024 to 0.02, p = 0.11), whereas higher straylight values (0.09; -0.01 to 0.20, p = 0.09) were observed in subjects with blue irises as compared to dark-colored irises when correcting for age. The intraclass correlation coefficient (ICC) of repeated measurements was 0.83 (95%CI 0.76 to 0.90). CONCLUSIONS: Our study showed that straylight measurements with the C-Quant had a high reproducibility, i.e. a lack of large intra-observer variability, making it appropriate to be applied in long-term follow-up studies assessing the long-term effect of surgical procedures on the quality of vision.