179 resultados para screening methods
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)
Resumo:
The aim of this study was to research Candida dubliniensis among isolates present in a Brazilian yeast collection and to evaluate the main phenotypic methods for discrimination between C. albicans and C. dubliniensis from oral cavity. A total of 200 isolates, presumptively identified as C. albicans or C. dubliniensis obtained from heart transplant patients under immunosuppressive therapy, tuberculosis patients under antibiotic therapy, HIV-positive patients under antiretroviral therapy, and healthy subjects, were analyzed using the following phenotypic tests: formation and structural arrangement of chlamydospores on corn meal agar, casein agar, tobacco agar, and sunflower seed agar; growth at 45 degrees C; and germ tube formation. All strains were analyzed by polymerase chain reaction (PCR). In a preliminary screen for C. dubliniensis, 48 of the 200 isolates on corn meal agar, 30 of the 200 on casein agar, 16 of the 200 on tobacco agar, and 15 of the 200 on sunflower seed agar produced chlamydoconidia; 27 of the 200 isolates showed no or poor growth at 45 degrees C. All isolates were positive for germ tube formation. These isolates were considered suggestive of C. dubliniensis. All of them were subjected to PCR analysis using C. dubliniensis-specific primers. C. dubliniensis isolates were not found. C. dubliniensis isolates were not recovered in this study done with immunocompromised patients. Sunflower seed agar was the medium with the smallest number of isolates of C. albicans suggestive of C. dubliniensis. None of the phenotypic methods was 100% effective for discrimination between C. albicans and C. dubliniensis. (C) 2011 Elsevier Inc. All rights reserved.
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Anemia screening before blood donation requires an accurate, quick, practical, and easy method with minimal discomfort for the donors. The aim of this study was to compare the accuracy of two quantitative methods of anemia screening: the HemoCue 201(+) (Aktiebolaget Leo Diagnostics) hemoglobin (Hb) and microhematocrit (micro-Hct) tests. Two blood samples of a single fingerstick were obtained from 969 unselected potential female donors to determine the Hb by HemoCue 201(+) and micro-Hct using HemataSTAT II (Separation Technology, Inc.), in alternating order. From each participant, a venous blood sample was drawn and run in an automatic hematology analyzer (ABX Pentra 60, ABX Diagnostics). Considering results of ABX Pentra 60 as true values, the sensitivity and specificity of HemoCue 201(+) and micro-Hct as screening methods were compared, using a venous Hb level of 12.0 g per dL as cutoff for anemia. The sensitivities of the HemoCue 201(+) and HemataSTAT II in detecting anemia were 56 percent (95% confidence interval [CI], 46.1%-65.5%) and 39.5 percent (95% CI, 30.2%-49.3%), respectively (p < 0.001). Analyzing only candidates with a venous Hb level lower than 11.0 g per dL, the deferral rate was 100 percent by HemoCue 201(+) and 77 percent by HemataSTAT II. The specificities of the methods were 93.5 and 93.2 percent, respectively. The HemoCue 201(+) showed greater discriminating power for detecting anemia in prospective blood donors than the micro-Hct method. Both presented equivalent deferral error rates of nonanemic potential donors. Compared to the micro-Hct, HemoCue 201(+) reduces the risk of anemic female donors giving blood, specially for those with lower Hb levels, without increasing the deferral of nonanemic potential donors.
Resumo:
Background: Mutations in TP53 are common events during carcinogenesis. In addition to gene mutations, several reports have focused on TP53 polymorphisms as risk factors for malignant disease. Many studies have highlighted that the status of the TP53 codon 72 polymorphism could influence cancer susceptibility. However, the results have been inconsistent and various methodological features can contribute to departures from Hardy-Weinberg equilibrium, a condition that may influence the disease risk estimates. The most widely accepted method of detecting genotyping error is to confirm genotypes by sequencing and/or via a separate method. Results: We developed two new genotyping methods for TP53 codon 72 polymorphism detection: Denaturing High Performance Liquid Chromatography (DHPLC) and Dot Blot hybridization. These methods were compared with Restriction Fragment Length Polymorphism (RFLP) using two different restriction enzymes. We observed high agreement among all methodologies assayed. Dot-blot hybridization and DHPLC results were more highly concordant with each other than when either of these methods was compared with RFLP. Conclusions: Although variations may occur, our results indicate that DHPLC and Dot Blot hybridization can be used as reliable screening methods for TP53 codon 72 polymorphism detection, especially in molecular epidemiologic studies, where high throughput methodologies are required.
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Advances in diagnostic research are moving towards methods whereby the periodontal risk can be identified and quantified by objective measures using biomarkers. Patients with periodontitis may have elevated circulating levels of specific inflammatory markers that can be correlated to the severity of the disease. The purpose of this study was to evaluate whether differences in the serum levels of inflammatory biomarkers are differentially expressed in healthy and periodontitis patients. Twenty-five patients (8 healthy patients and 17 chronic periodontitis patients) were enrolled in the study. A 15 mL blood sample was used for identification of the inflammatory markers, with a human inflammatory flow cytometry multiplex assay. Among 24 assessed cytokines, only 3 (RANTES, MIG and Eotaxin) were statistically different between groups (p<0.05). In conclusion, some of the selected markers of inflammation are differentially expressed in healthy and periodontitis patients. Cytokine profile analysis may be further explored to distinguish the periodontitis patients from the ones free of disease and also to be used as a measure of risk. The present data, however, are limited and larger sample size studies are required to validate the findings of the specific biomarkers.
Resumo:
Introduction: Cervical and breast cancer are the most common malignancies among women worldwide. Effective screening can facilitate early detection and dramatically reduce mortality rates. The interface between those screening patients and patients most needing screening is complex, and women in remote areas of rural counties face additional barriers that limit the effectiveness of cancer prevention programs. This study compared various methods to improve compliance with mass screening for breast and cervical cancer among women in a remote, rural region of Brazil. Methods: In 2003, a mobile unit was used to perform 10 156 mammograms and Papanicolaou smear tests for women living in the Barretos County region of Sao Paulo state, Brazil (consisting of 19 neighbouring cities). To reach the women, the following community outreach strategies were used: distribution of flyers and pamphlets; media broadcasts (via radio and car loudspeakers); and community healthcare agents (CHCAs) making home visits. Results: The most useful intervention appeared to be the home visits by healthcare agents or CHCAs. These agents of the Family Health Programme of the Brazilian Ministry of Health reached an average of 45.6% of those screened, with radio advertisements reaching a further 11.9%. The great majority of the screened women were illiterate or had elementary level schooling (80.9%) and were of 'poor' or 'very poor' socioeconomic class (67.2%). Conclusions: Use of a mobile screening unit is a useful strategy in developing countries where local health systems have inadequate facilities for cancer screening in underserved populations. A multimodal approach to community outreach strategies, especially using CHCAs and radio advertisements, can improve the uptake of mass screening in low-income, low-educational background female populations.
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Background: Although the Clock Drawing Test (CDT) is the second most used test in the world for the screening of dementia, there is still debate over its sensitivity specificity, application and interpretation in dementia diagnosis. This study has three main aims: to evaluate the sensitivity and specificity of the CDT in a sample composed of older adults with Alzheimer`s disease (AD) and normal controls; to compare CDT accuracy to the that of the Mini-mental State Examination (MMSE) and the Cambridge Cognitive Examination (CAMCOG), and to test whether the association of the MMSE with the CDT leads to higher or comparable accuracy as that reported for the CAMCOG. Methods: Cross-sectional assessment was carried out for 121 AD and 99 elderly controls with heterogeneous educational levels from a geriatric outpatient clinic who completed the Cambridge Examination for Mental Disorder of the Elderly (CAMDEX). The CDT was evaluated according to the Shulman, Mendez and Sunderland scales. Results: The CDT showed high sensitivity and specificity. There were significant correlations between the CDT and the MMSE (0.700-0.730; p < 0.001) and between the CDT and the CAMCOG (0.753-0.779; p < 0.001). The combination of the CDT with the MMSE improved sensitivity and specificity (SE = 89.2-90%; SP = 71.7-79.8%). Subgroup analysis indicated that for elderly people with lower education, sensitivity and specificity were both adequate and high. Conclusions: The CDT is a robust screening test when compared with the MMSE or the CAMCOG, independent of the scale used for its interpretation. The combination with the MMSE improves its performance significantly, becoming equivalent to the CAMCOG.
Resumo:
This paper describes an analytical method for the rapid screening and identification of the phenolic constituents present in the polar extracts of different Lychnophora spp. using LC-UV/DAD-ESI-MS and LC-UV/DAD-ESI-MS/MS. Compounds were identified based on UV, retention time, MS experiments and MS/MS of precursor ion or standard. On-line phytochemical investigation of Lychnophora spp. allowed for the identification of flavonoids, chlorogenic acid derivatives and lactones. Some of the observed compounds were for the first time identified in Lychnophora species in a fast analytical procedure. The data obtained here may be helpful to the investigation of polar constituents from other Lychnophora species.
Resumo:
Introduction. Hepatic steatosis due to non-alcoholic fatty liver disease is associated with obesity, dyslipidemia, insulin resistance, and type 2 diabetes. The Finnish Diabetes Risk Score (FINDRISC) is a prognostic screening tool to detect people at risk for type 2 diabetes without the use of any blood test. The objective of this study was to evaluate whether FINDRISC can also be used to screen for the presence of hepatic steatosis. Patients and methods. Steatosis was determined by ultrasound. The study sample consisted of 821 non-diabetic subjects without previous hepatic disease; 81% were men (mean age 45 +/- 9 years) and 19% women (mean age 41 +/- 10 years). Results. Steatosis was present in 44% of men and 10% of women. The odds ratio for one unit increase in the FINDRISC associated with the risk of steatosis was 1.30 (95% CI 1.25-1.35), similar for men and women. The area under the receiver operating characteristics curve for steatosis was 0.80 (95% CI 0.77-0.83); 0.80 in men (95% CI 0.77-0.83) and 0.83 (95% CI 0.73-0.93) in women. Conclusions. Our data suggest that the FINDRISC could be a useful primary screening tool for the presence of steatosis.
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Background Meta-analysis is increasingly being employed as a screening procedure in large-scale association studies to select promising variants for follow-up studies. However, standard methods for meta-analysis require the assumption of an underlying genetic model, which is typically unknown a priori. This drawback can introduce model misspecifications, causing power to be suboptimal, or the evaluation of multiple genetic models, which augments the number of false-positive associations, ultimately leading to waste of resources with fruitless replication studies. We used simulated meta-analyses of large genetic association studies to investigate naive strategies of genetic model specification to optimize screenings of genome-wide meta-analysis signals for further replication. Methods Different methods, meta-analytical models and strategies were compared in terms of power and type-I error. Simulations were carried out for a binary trait in a wide range of true genetic models, genome-wide thresholds, minor allele frequencies (MAFs), odds ratios and between-study heterogeneity (tau(2)). Results Among the investigated strategies, a simple Bonferroni-corrected approach that fits both multiplicative and recessive models was found to be optimal in most examined scenarios, reducing the likelihood of false discoveries and enhancing power in scenarios with small MAFs either in the presence or in absence of heterogeneity. Nonetheless, this strategy is sensitive to tau(2) whenever the susceptibility allele is common (MAF epsilon 30%), resulting in an increased number of false-positive associations compared with an analysis that considers only the multiplicative model. Conclusion Invoking a simple Bonferroni adjustment and testing for both multiplicative and recessive models is fast and an optimal strategy in large meta-analysis-based screenings. However, care must be taken when examined variants are common, where specification of a multiplicative model alone may be preferable.
Resumo:
Objective: International nutritional screening tools are recommended for screening hospitalized patients for nutritional risk, but no tool has been specifically evaluated in the Brazilian population. The aim of this study was to identify the most appropriate nutritional screening tool for predicting unfavorable clinical outcomes in patients admitted to a Brazilian public university hospital. Methods: The Nutritional Risk Screening 2002 (NRS 2002), Mini-Nutritional Assessment-Short Form (MNA-SF), and Malnutrition Universal Screening Tool (MUST) were administered to 705 patients within 48 h of hospital admission. Tool performance in predicting complications, very long length of hospital stay (LOS), and death was analyzed using receiver operating characteristic curves. Results: NRS 2002, MUST, and MNA-SF identified nutritional risk in 27.9%, 39.6%, and 73.2% of the patients, respectively. NRS 2002 (complications: 0.6531; very long LOS: 0.6508; death: 0.7948) and MNA-SF(complications: 0.6495; very long LOS: 0.6197; death: 0.7583) had largest areas under the ROC curve compared to MUST (complications: 0.6036; very long LOS: 0.6109; death: 0.6363). For elderly patients, NRS 2002 was not significantly different than MNA-SF (P>0.05) for predicting outcomes. Conclusion: Considering current criteria for nutritional risk, NRS 2002 and MNA-SF have similar performance to predict outcomes but NRS 2002 seems to provide a best yield. (C) 2010 Elsevier Inc. All rights reserved.
Resumo:
PURPOSE: The purpose of this study was to analyze the agreement between anal Pap smear and high-resolution anoscopy-guided biopsy in diagnosing anal dysplasia in HIV-infected patients. METHODS: We conducted cross-sectional analysis of HIV-infected patients receiving anal dysplasia screening as part of routine care. Agreement between measures was estimated by weighted kappa statistics, using a three-tiered cytologic and histologic grading system (normal, low-grade dysplasia, and high-grade dysplasia). Estimates of sensitivity, specificity, and predictive values were calculated using a two-tiered cytologic and histologic grading system (""without dysplasia"" and ""with dysplasia of any grade""). Estimates were also calculated for the detection of high-grade dysplasia. RESULTS: During a one-year period, 222 patients underwent 330 anal Pap smears followed by high-resolution anoscopy-guided biopsies. There were 311 satisfactory Pap smears with concurrent biopsies. Considering histology the standard, the frequency of anal dysplasia was 46%. Kappa agreement between anal Pap smear and biopsy was 0.20. For detection of anal dysplasia of any grade, anal Pap smear showed sensitivity of 61%, specificity of 60%, positive predictive value of 56%, and negative predictive value of 64%. For high-grade dysplasia, anal Pap smear showed sensitivity of 16% and specificity of 97%. CONCLUSION: Anal Pap smears alone were not sensitive enough to rule out anal dysplasia. We recommend that high-resolution anoscopy-guided biopsy be incorporated as a complementary screening test for anal dysplasia in high-risk patients. Following baseline high-resolution anoscopy, these individuals could be followed with serial anal cytology to dictate the need for future high-resolution anoscopy-guided biopsies.
Resumo:
Objective. The purpose of this study was to estimate the Down syndrome detection and false-positive rates for second-trimester sonographic prenasal thickness (PT) measurement alone and in combination with other markers. Methods. Multivariate log Gaussian modeling was performed using numerical integration. Parameters for the PT distribution, in multiples of the normal gestation-specific median (MoM), were derived from 105 Down syndrome and 1385 unaffected pregnancies scanned at 14 to 27 weeks. The data included a new series of 25 cases and 535 controls combined with 4 previously published series. The means were estimated by the median and the SDs by the 10th to 90th range divided by 2.563. Parameters for other markers were obtained from the literature. Results. A log Gaussian model fitted the distribution of PT values well in Down syndrome and unaffected pregnancies. The distribution parameters were as follows: Down syndrome, mean, 1.334 MoM; log(10) SD, 0.0772; unaffected pregnancies, 0.995 and 0.0752, respectively. The model-predicted detection rates for 1%, 3%, and 5% false-positive rates for PT alone were 35%, 51%, and 60%, respectively. The addition of PT to a 4 serum marker protocol increased detection by 14% to 18% compared with serum alone. The simultaneous sonographic measurement of PT and nasal bone length increased detection by 19% to 26%, and with a third sonographic marker, nuchal skin fold, performance was comparable with first-trimester protocols. Conclusions. Second-trimester screening with sonographic PT and serum markers is predicted to have a high detection rate, and further sonographic markers could perform comparably with first-trimester screening protocols.
Resumo:
Aim: To compare cervical length (CL) at 18-21 and 22-25 weeks` gestation in twin pregnancies in prediction of spontaneous preterm delivery and to examine cervical shortening. Methods: Retrospective cohort study of CL measured at 18-21 and 22-25 weeks` gestation in twin pregnancies. Results: Receiver operating characteristics (ROC) curve revealed area of 0.64 (95% CI 0.53-0.75) and 0.80 (95% CI 0.72-0.88) for measurements at 18-21 and 22-25 weeks, respectively (P <= 0.001). Sensitivities of 33.3% and 23% and negative predicting value (NPV) of 97.3% and 86.8% for delivery at <28 and <34 weeks gestation were reached for measurements at 18-21 weeks. Sensitivities of 71.4% and 38.2% and NPV of 99.1% and 91.4% for delivery at <28 and <34 weeks` gestation were reached for measurements at 22-25 weeks. Cervical length shortening analysis showed an area under ROC curve of 0.81 (95% CI 0.73-0.89) and best cut-off was at >= 2 mm/week. Sensitivities of 80% and 60.8% and NPV of 98.9% and 90.6% for delivery at <28 and <34 weeks gestation were reached. Conclusions: In twin gestations, assessment of CL at 22-25 weeks is better than assessment at 18-21 weeks to predict preterm delivery before 34 weeks. Cervical shortening at a rate of >= 2 mm/weeks between 18 and 25 weeks gestation was a good predictor of spontaneous preterm birth in this high-risk population.
Resumo:
Objective: To identify the CAMCOG sub-items that best contribute for the identification of patients with mild cognitive impairment (MCI) and incipient Alzheimer`s disease (AD) in clinical practice. Methods: Cross-sectional assessment of 272 older adults (98 MCI, 82 AD, and 92 controls) with a standardized neuropsychological battery and the CAMCOG schedule. Backward logistic regression analysis with diagnosis (MCI and controls) as dependent variable and the sub-items of the CAMCOG as independent variable was carried out to determine the CAMCOG sub-items that predicted the diagnosis of MCI. Results: Lower scores on Language, Memory, Praxis, and Calculation CAMCOG sub-items were significantly associated with the diagnosis of MCI. A composite score obtained by the sum of these scores significantly discriminated MCI patients from comparison groups. This reduced version of the CAMCOG showed similar diagnostic accuracy than the original schedule for the identification of patients with MCI as compared to controls (AUC = 0.80 +/- 0.03 for the reduced CAMCOG; AUC = 0.79 +/- 0.03 for the original CAMCOG). Conclusion: This reduced version of the CAMCOG had similar diagnostic properties as the original CAMCOG and was faster and easier to administer, rendering it more suitable for the screening of subtle cognitive deficits in general clinical practice. Copyright (C) 2010 John Wiley & Sons, Ltd.
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OBJECTIVES To evaluate the initial results of a prostate cancer screening program using mobile units in Brazil. METHODS Since 2004, we have conducted a program of prostate cancer screening using mobile units across 231 municipalities from 6 Brazilian states. RESULTS A total of 17 571 men were evaluated by clinical history, digital rectal examination (DRE), and serum free and total prostate-specific antigen (PSA) levels. The recommendations for biopsy were a PSA level of >= 4.0 ng/mL, DRE findings suspicious for cancer, or a PSA level of 2.5-4.0 ng/mL with a percent-free PSA level <15%. The biopsy protocol included 12 biopsy cores from the peripheral zone, 2 from the transition zone, and additional sampling of suspicious areas. The cumulative cancer detection rate was 3.7%. The main indication for biopsy was a PSA level of >= 4.0 ng/mL (51.2%), with a positive predictive value (PPV) of 44.1%. Another 19.7% of biopsied men had suspicious DRE findings with a normal PSA level (PPV 23.5%). A percent-free PSA level of <15% in men with a PSA level of 2.5-4.0 ng/mL and normal DRE findings yielded a PPV of 31.1%. The PPV was greater (70.9%) for the 7.1% of men with both suspicious DRE findings and a PSA level of >4.0 ng/mL. Most cancers were Stage T1-T2 (93.4%), and the percentage of Gleason score of >= 7 was 32.5%. The proportion of insignificant cancers according to Epstein`s criteria was 13.5%. CONCLUSIONS A mobile prostate cancer screening unit enabled an underserved population to gain access to specialized care through the public healthcare system. The cancer detection rate in this population was similar to those from international studies. UROLOGY 76: 1052-1057, 2010. (C) 2010 Published by Elsevier Inc.