978 resultados para False confession
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The aim of this study was to validate the rapid lateral flow Helicobacter pylori stool antigen test (One step H. pylori antigen test, ACON laboratories, San Diego, USA; Prime diagnostics, São Paulo), using 13C-Urea Breath Test as the gold standard for H. pylori infection diagnosis. A total of 98 consecutive patients, asymptomatic or dyspeptic, entered the study. Sixty-nine were women, with a mean age of 45.76 ± 14.59 years (14 to 79 years). In the H. pylori-positive group, the rapid stool antigen test detected H. pylori antigen in 44 of the 50 positive patients (sensitivity 88%; 95% CI: 75.7-95.5%), and six false-negative; and in the H. pylori-negative group 42 presented negative results (specificity 87.5%; 95% CI: 74.7-95.3%), and six false-positive, showing a substantial agreement (Kappa Index = 0.75; p < 0.0001; 95% CI: 0.6-0.9). Forty four of fifty patients that had positive stool antigen were H. pylori-positive, the PPV of the stool antigen test was 88% (95% CI: 75.7-95.5%), and 42 patients with negative stool antigen test were H. pylori-negative, the NPV of the stool antigen test was 87.5% (95% CI: 74.7-95.3%). We conclude that the lateral flow stool antigen test can be used as an alternative to breath test for H. pylori infection diagnosis especially in developing countries.
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The purpose of our study was to evaluate the accuracy of dynamic incremental bolus-enhanced conventional CT (DICT) with intravenous contrast administration, early phase, in the diagnosis of malignancy of focal liver lesions. A total of 122 lesions were selected in 74 patients considering the following criteria: lesion diameter 10 mm or more, number of lesions less than six per study, except in multiple angiomatosis and the existence of a valid criteria of definitive diagnosis. Lesions were categorized into seven levels of diagnostic confidence of malignancy compared with the definitive diagnosis for acquisition of a receiver-operator-characteristic (ROC) curve analysis and to determine the sensitivity and specificity of the technique. Forty-six and 70 lesions were correctly diagnosed as malignant and benign, respectively; there were 2 false-positive and 4 false-negative diagnoses of malignancy and the sensitivity and specificity obtained were 92 and 97%. The DICT early phase was confirmed as a highly accurate method in the characterization and diagnosis of malignancy of focal liver lesions, requiring an optimal technical performance and judicious analysis of existing semiological data.
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INTRODUCTION: Predicting outcome in comatose survivors of cardiac arrest is based on data validated by guidelines that were established before the era of therapeutic hypothermia. We sought to evaluate the predictive value of clinical, electrophysiological and imaging data on patients submitted to therapeutic hypothermia. MATERIALS AND METHODS: A retrospective analysis of consecutive patients receiving therapeutic hypothermia during years 2010 and 2011 was made. Neurological examination, somatosensory evoked potentials, auditory evoked potentials, electroencephalography and brain magnetic resonance imaging were obtained during the first 72 hours. Glasgow Outcome Scale at 6 months, dichotomized into bad outcome (grades 1 and 2) and good outcome (grades 3, 4 and 5), was defined as the primary outcome. RESULTS: A total of 26 patients were studied. Absent pupillary light reflex, absent corneal and oculocephalic reflexes, absent N20 responses on evoked potentials and myoclonic status epilepticus showed no false-positives in predicting bad outcome. A malignant electroencephalographic pattern was also associated with a bad outcome (p = 0.05), with no false-positives. Two patients with a good outcome showed motor responses no better than extension (false-positive rate of 25%, p = 0.008) within 72 hours, both of them requiring prolonged sedation. Imaging findings of brain ischemia did not correlate with outcome. DISCUSSION: Absent pupillary, corneal and oculocephalic reflexes, absent N20 responses and a malignant electroencephalographic pattern all remain accurate predictors of poor outcome in cardiac arrest patients submitted to therapeutic hypothermia. CONCLUSION: Prolonged sedation beyond the hypothermia period may confound prediction strength of motor responses.
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Schistosomiasis constitutes a major public health problem, with an estimated 200 million individuals infected worldwide and 700 million people living in risk areas. In Brazil there are areas of high, medium and low endemicity. Studies have shown that in endemic areas with a low prevalence of Schistosoma infection the sensitivity of parasitological methods is clearly reduced. Consequently diagnosis is often impeded due to the presence of false-negative results. The aim of this study is to present the PCR reamplification (Re-PCR) protocol for the detection of Schistosoma mansoni in samples with low parasite load (with less than 100 eggs per gram (epg) of feces). Three methods were used for the lysis of the envelopes of the S. mansoni eggs and two techniques of DNA extraction were carried out. Extracted DNA was quantified, and the results suggested that the extraction technique, which mixed glass beads with a guanidine isothiocyanate/phenol/chloroform (GT) solution, produced good results. PCR reamplification was conducted and detection sensitivity was found to be five eggs per 500 mg of artificially marked feces. The results achieved using these methods suggest that they are potentially viable for the detection of Schistosoma infection with low parasite load.
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Objectives: To retrospectively review the hybrid treatment of the aortic arch with supra-aortic debranching and endo- vascular stent-graft repair in a single institution. Methods: From 2007 to 2010, all patients submitted to aortic debranching procedures were entered into a prospective database analysis. For the present study, only patients with sealing zones 0 and 1, according to the Ishimaru classification, were included. Procedure-related morbimortality was analysed for the open and endovascular procedures. Results: During the study period, we electively performed 6 total aortic debranching and 4 partial aortic debranching procedures in 10 patients. According to the etiology the indications were: 6 aortic arch aneurysms, 2 post-dissection aneu- rysms, 1 false aneurysm and 1 type I endoleak following TEVAR. The proximal sealing zone was Ishimaru zone 0 in six patients and zone 1 in four patients. The TEVAR procedure was delayed in all patients with a completion success of 80% (1 patient died from ruptured aortic aneurysm; 1 patient denied the second procedure and was lost to follow-up). The 30d mortality rate was 10% (patient mentioned above). The main morbidity was: 1 axillar venous thrombosis, 1 case of subclinical myocardial infarction, 1 case of terminal renal insufficiency and 1 case of prolonged ventilation. No permanent cerebral or peripheral neurologic deficit was noted. Conclusions: The hybrid repair of the aortic arch is a feasible and reproducible procedure, and our results are similar to the previously published series. Medium and long-term results are necessary to confirm whether the technique can be regarded as a safe alternative to open surgery in high-risk patients.
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The clinical application of CCR5 antagonists involves first determining the coreceptor usage by the infecting viral strain. Bioinformatics programs that predict coreceptor usage could provide an alternative method to screen candidates for treatment with CCR5 antagonists, particularly in countries with limited financial resources. Thus, the present study aims to identify the best approach using bioinformatics tools for determining HIV-1 coreceptor usage in clinical practice. Proviral DNA sequences and Trofile results from 99 HIV-1-infected subjects under clinical monitoring were analyzed in this study. Based on the Trofile results, the viral variants present were 81.1% R5, 21.4% R5X4 and 1.8% X4. Determination of tropism using a Geno2pheno[coreceptor] analysis with a false positive rate of 10% gave the most suitable performance in this sampling: the R5 and X4 strains were found at frequencies of 78.5% and 28.4%, respectively, and there was 78.6% concordance between the phenotypic and genotypic results. Further studies are needed to clarify how genetic diversity amongst virus strains affects bioinformatics-driven approaches for determining tropism. Although this strategy could be useful for screening patients in developing countries, some limitations remain that restrict the wider application of coreceptor usage tests in clinical practice.
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Candida albicans is often isolated from clinical samples, thus its presumptive differentiation from other species of the same genus can be based on its ability to form the germ tube in human serum. Nevertheless, there are two other species that share this characteristic: C. dubliniensis and C. africana. The aim of this study was to compare four different substrates to perform the germ tube (GT) test. The Candida spp. isolates were identified using a manual system (135 C. albicans, 24 C. tropicalis and one C. dubliniensis). The germ tube test was performed with fresh, previously frozen serum and Mueller-Hinton (MH) broth and agar. GT was observed in 96% (130/136) of the isolates through the fresh serum technique, 94% (128/136) through previously frozen serum, 92% (125/136) in MH agar, and 90% (122/136) in MH broth. The sensitivity of each test was higher than 90%, with 100% specificity. Both the MH agar and broth were able to identify the true positives, and false positives were not found. However, some C. albicans isolates were not identified. MH agar and broth may be used in laboratory for the rapid presumptive identification of C. albicans, as an alternative method for germ tube test.
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Pseudoaneurysms of the ascending aorta are a rare complication of cardiac surgery. However, the poor prognosis associated with this condition if untreated makes early diagnosis and treatment important. We present the case of a 66-year-old woman who had undergone mitral valvuloplasty 12 days previously, who was admitted with a diagnosis of new-onset atrial fibrillation. The transthoracic echocardiogram showed a clot in the right atrium and anticoagulation was initiated, followed by antibiotic therapy. After further investigation, the patient was diagnosed with a pseudoaneurysm of the ascending aorta and underwent surgical repair, followed by six weeks of antibiotic therapy. She was readmitted six months later for an abscess of the lower sternum and mediastinum. After a conservative approach with antibiotics and local drainage failed, recurrence of a large pseudoaneurysm compressing the superior vena cava was documented. A third operation was performed to debride the infected tissue and to place an aortic allograft. There were no postoperative complications.
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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores
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Objective:We aimed to identify the cut-off for risk of pre-eclampsia (PE) in Portuguese population by applying the first trimester prediction model from Fetal Medicine Foundation (FMF) in a prospective enrolled cohort of low risk pregnant women. Population and methods: A prospective cohort of low risk singleton pregnancies underwent routine first-trimester scree - ning from 2011 through 2013. Maternal characteristics, blood pressure, uterine artery Doppler, levels of pregnancy-associated plasma protein-A (PAPP-A) and free b-human chorionic gonadotropin were evaluated. The prediction of PE in first trimester was calculated through software Astraia, the outcome obtained from medical records and the cutoff value was subse quently calculated. Results:Of the 273 enrolled patients, 7 (2.6%) developed PE. In first trimester women who developed PE presented higher uterine arteries resistance, represented by higher values of lowest and mean uterine pulsatility index, p <0.005. There was no statistical significance among the remaining maternal characteristics, body mass index, blood pressure and PAPP-A. Using the FMF first trimester PE algorithm, an ideal cut-off of 0.045 (1/22) would correctly detect 71% women who developed PE for a 12% false positive rate and a likelihood ratio of 12.98 (area under the curve: 0.69; confidence interval 95%: 0.39-0.99). By applying the reported cutoff to our cohort, we would obtain 71.4% true positives, 88.3% true negatives, 11.4% false positives and 28.6% false negatives. Conclusion: By applying a first trimester PE prediction model to low risk pregnancies derived from a Portuguese population, a significant proportion of patients would have been predicted as high risk. New larger studies are required to confirm the present findings.
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Canine brains infected with rabies virus were submitted to decomposition by being left at room temperature of 25 to 29oC for up to 168h. At 24h intervals, brain fragments were analyzed by immunofluorescence (IF) and by the mouse intracerebral inoculation (MI) test to confirm the diagnosis of rabies and to measure the putrefaction effect on the accuracy of the diagnosis. Forty eight h after the beginning of the experiment, the MI test showed signs of impairment with four negative results, while after 72h, 100% of the results were negative to the MI test and only one result was negative to the IF test, indicating that the threshold period for accurate diagnosis is 24 to 48h before putrefaction. The authors recommend the shipment of suspected cases of rabies to the laboratory for confirmation, but the use of putrid materials for diagnosis is meaningless because of false-negative results.
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Dissertação para obtenção do Grau de Doutora em Estatística e Gestão de Risco, Especialidade em Estatística
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RESUMO: As Análises Clínicas são um precioso elemento entre os meios complementares de diagnóstico e terapêutica permitindo uma enorme panóplia de informações sobre o estado de saúde de determinado utente. O objetivo do laboratório é fornecer informação analítica sobre as amostras biológicas, sendo esta caracterizada pela sua fiabilidade, relevância e facultada em tempo útil. Assim, tratando-se de saúde, e mediante o propósito do laboratório, é notória a sua importância, bem como, a dos fatores associados para o cumprimento do mesmo. O bom desenrolar do ciclo laboratorial, compreendido pelas fases pré-analítica, analítica e pós-analítica é crucial para que o objetivo do laboratório seja cumprido com rigor e rapidez. O presente trabalho “O Erro na Fase Pré-Analítica: Amostras Não Conformes versus Procedimentos”, enquadrado no mestrado de Qualidade e Organização no Laboratório de Análises Clínicas, pretendeu enfatizar a importância da fase pré- analítica, sendo ela apontada como a primordial em erros que acabam por atrasar a saída de resultados ou por permitir que os mesmos não sejam fidedignos como se deseja, podendo acarretar falsos diagnósticos e decisões clínicas erradas. Esta fase, iniciada no pedido médico e finalizada com a chegada das amostras biológicas ao laboratório está entregue a uma diversidade de procedimentos que acarretam, por si só, uma grande diversidade de intervenientes, para além de uma variabilidade de factores que influenciam a amostra e seus resultados. Estes fatores, que podem alterar de algum modo a “veracidade” dos resultados analíticos, devem ser identificados e tidos em consideração para que estejamos convitos que os resultados auxiliam diagnósticos precisos e uma avaliação correta do estado do utente. As colheitas que por quaisquer divergências não originam amostras que cumpram o objectivo da sua recolha, não estando por isso em conformidade com o pretendido, constituem uma importante fonte de erro para esta fase pré-analítica. Neste estudo foram consultados os dados relativos a amostras de sangue e urina não conformes detetadas no laboratório, em estudo, durante o 1º trimestre de 2012, para permitir conhecer o tipo de falhas que acontecem e a sua frequência. Aos Técnicos de Análises Clínicas, colaboradores do laboratório, foi-lhes pedido que respondessem a um questionário sobre os seus procedimentos quotidianos e constituíssem, assim, a população desta 2ª parte do projeto. Preenchido e devolvido de forma anónima, este questionário pretendeu conhecer os procedimentos na tarefa de executar colheitas e, hipoteticamente, confrontá-los com as amostras não conformes verificadas. No 1ºsemestre de 2012 e num total de 25319 utentes registaram-se 146 colheitas que necessitaram de repetição por se verificarem não conformes. A “amostra não colhida” foi a não conformidade mais frequente (50%) versus a “má identificação” que registou somente 1 acontecimento. Houve ainda não conformidades que não se registaram como “preparação inadequada” e “amostra mal acondicionada”. Os técnicos revelaram-se profissionais competentes, conhecedores das tarefas a desempenhar e preocupados em executá-las com qualidade. Eliminar o erro não estará, seguramente, ao nosso alcance porém admitir a sua presença, detetá-lo e avaliar a sua frequência fará com que possamos diminuir a sua existência e melhorar a qualidade na fase pré-analítica, atribuindo-lhe a relevância que desempenha no processo laboratorial.-----------ABSTRACT:Clinical analyses are a precious element among diagnostic and therapeutic tests as they allow an enormous variety of information on the state of health of a user. The aim of the laboratory is to supply reliable, relevant and timely analytical information on biological samples. In health-related matters, in accordance with the objective of the laboratory, their importance is vital, as is the assurance that all the tools are in place for the fulfillment of its purpose. A good laboratory cycle, which includes the pre-analytical, analytical and post-analytical phases, is crucial in fulfilling the laboratory’s mission rapidly and efficiently. The present work - "Error in the pre-analytical phase: non-compliant samples versus procedures”, as part of the Master’s in Quality and Organization in the Clinical Analyses Laboratory, wishes to emphasize the importance of the pre-analytical phase, as the phase containing most errors which eventually lead to delays in the issue of results, or the one which enables those results not to be as reliable as desired, which can lead to false diagnosis and wrong clinical decisions. This phase, which starts with the medical request and ends with the arrival of the biological samples to the laboratory, entails a variety of procedures, which require the intervention of different players, not to mention a great number of factors, which influence the sample and the results. These factors, capable of somehow altering the “truth” of the analytical results, must be identified and taken into consideration so that we may ensure that the results help to make precise diagnoses and a correct evaluation of the user’s condition. Those collections which, due to any type of differences, do not originate samples capable of fulfilling their purpose, and are therefore not compliant with the objective, constitute an important source of error in this pre-analytical phase. In the present study, we consulted data from non-compliant blood and urine samples, detected at the laboratory during the 1st quarter of 2012, to find out the type of faults that happen and their frequency. The clinical analysis technicians working at the laboratory were asked to fill out a questionnaire regarding their daily procedures, forming in this way the population for this second part of the project. Completed and returned anonymously, this questionnaire intended to investigate the procedures for collections and, hypothetically, confront them with the verified non-compliant samples. In the first semester of 2012, and out of a total of 25319 users, 146 collections had to be repeated due to non-compliance. The “uncollected sample” was the most frequent non-compliance (>50%) versus “incorrect identification” which had only one occurrence. There were also unregistered non-compliance issues such as “inadequate preparation” and “inappropriately packaged sample”. The technicians proved to be competent professionals, with knowledge of the tasks they have to perform and eager to carry them out efficiently. We will certainly not be able to eliminate error, but recognizing its presence, detecting it and evaluating its frequency will help to decrease its occurrence and improve quality in the pre-analytical phase, giving it the relevance it has within the laboratory process.
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RESUMO: Contexto: As anomalias congénitas, com particular destaque para as neuploidias , afectam aproximadamente 2% dos recém-nascidos, constituindo causas frequentes de morbilidade e mortalidade. Actualmente, a avaliação do grau de risco para as aneuploidias mais prevalentes (T21, T13, T18) é efectuada através do “Rastreio Combinado do 1º Trimestre”, devendo as grávidas com risco acrescido ser sujeitas a exames invasivos (ex.biópsia das vilosidades coriónicas,amniocentese). Quanto mais qualidade existir num rastreio, menos falsos positivos existirão e menor o número de exames diagnósticos invasivos desnecessários. As doenças autoimunes são doenças inflamatórias crónicas em cuja fisiopatologia se encontram distúrbios da imunidade humoral e celular, dependentes de factores genéticos, hormonais,psicológicos e ambientais. Atingem mais o sexo feminino e durante a idade fértil,podendo influenciar o outcome da gravidez e a saúde neonatal causando significativa morbilidade e mortalidade. O lúpus eritematoso sistémico para além de potencialmente afectado pelas alterações imunoendócrinas fisiológicas da gravidez, associa-se frequentemente a problemas de fertilidade. Recentemente, foi sugerido que as anormalidades ocorridas durante a invasão precoce do sinciciotrofoblasto, resultando em deficiente diferenciação, deficiente maturação e diminuição na produção de hCG, poderão ser o mecanismo fisiopatológico primário para as perdas fetais no primeiro trimestre, nos doentes com SLE. A ocorrência de níveis elevados de hCG total e ß-hCG livre no rastreio para despiste de síndrome de Down do segundo e do primeiro trimestre foi assinalada em grávidas portadoras de lúpus, mas a escassez de estudos comprovativos e a pequena dimensão das amostras estudadas constituiu uma limitação significativa na fidedignidade dos resultados obtidos. Objectivos: O estudo teve como objectivos i. estabelecer valores normativos Portugueses e de distribuição para as MoM’s dos parâmetros séricos do primeiro trimestre, por semana de gestação:(PAPP-A e ß-hCG livre), ii. avaliar a influência que as doenças autoimunes têm sobre as MoM’s individuais dos parâmetros bioquímicos PAPP-A e/ou ß-hCG livre, utilizados no rastreio pré-natal combinado do 1º trimestre, e iii. saber se as doenças autoimunes podem condicionar um aumento da taxa de resultados falsos positivos, com consequente aumento do número de amniocenteses. Metodologia: Estudo longitudinal prospectivo, consistindo num rastreio pré-natal combinado de 1º trimestre para pesquisa de aneuploidias, em duas amostras provenientes do Reino Unido (n= 45,854) e de Portugal (n=3122). Foram avaliados parâmetros socio-demográficos, ecográficos, laboratoriais, e calculados os indicadores de desempenho do rastreio combinado. A execução analítica dos testes bioquímicos séricos (PAPP-A e ß-hCG livre) foi realizada no autoanalisador Brahms Kryptor e no autoanalizador 6000 Delfia Xpress. Compararam-se os grupos autoimune e não autoimune das amostras. Resultados: Relativamente às características populacionais, o grupo auto imune tinha valores significativamente superiores nas variáveis idade materna e idade gestacional. Comparando os grupos com e sem doença autoimune, constatou-se a existência de uma elevação das MoM’s da ß-hCG livre nas grávidas com doença autoimune, nomeadamente nos casos de lúpus eritematoso sistémico. Conclusões: os resultado obtidos reforçam a indicação do rastreio combinado do 1º trimestre certificado pela FMF nas grávidas com doenças autoimunes, nomeadamente para as doentes com LES; no entanto, devem ser calculados e introduzidos factores de correcção no algoritmo de risco, de modo a evitar a subida no número de resultados falso-positivos, e consequentemente a sobre- utilização de métodos invasivos.------------ ABSTRACT: Context: Congenital anomalies, with particular reference to aneuploidias, affect approximately 2% of newborns, and are frequent causes of morbidity and mortality. Currently, the risk evaluation for the most prevalent aneuploidias (T21, T13, T18) is carried out through the “combined first trimester screening”, and pregnant women with increased risk are subjected to invasive tests (e.g. villus biopsy done, amniocentesis). The more quality exists in a screening, less false positives exists and fewer unnecessary invasive diagnostic exams. Autoimmune diseases are chronic inflammatory diseases in whose pathophysiology are immune humoral and cellular disorders, dependent on genetic factors, hormonal, psychological and environmental factors. The disease is more prevalent among females, during the child-bearing age, and may influence the outcome of pregnancy and neonatal health causing significant morbidity and mortality. Lupus Erythematosus in addition to potentially affected by immunoendocrine physiological changes of pregnancy, is often associated with fertility problems. Recently, it has been suggested that the abnormalities that occurred during the early invasion of the syncytiotrophoblast, resulting in insufficient differentiation, deficient maturation and decrease in production of hCG may be the primary pathophysiological mechanism for fetal losses in the first quarter, in patients with SLE. The occurrence of elevated levels of total hCG and free ß-hCG in screening for Down’s syndrome of the second and first trimester was reported in pregnant women with lupus, but the paucity of supporting studies and the small size of the samples studied constituted a significant limitation on the trustworthiness of the results obtained. Objectives: this study aims to i. establish normative values for the serum parameters MoM’s (PAPP-A and free β-hCG) and it’s distribution, in the first trimester, by week of pregnancy; ii. assess the influence that the autoimmune diseases have on the MoM’s of individual biochemical PAPP-A and/or β-hCG, used in antenatal screening combined for the first trimester, and iii. whether the autoimmune diseases may make an increased rate of false positives, with consequent increase in the number of amniocenteses.Methodology: Prospective longitudinal study, consisting of a combined first trimester antenatal screening for aneuploidies lookup in two samples from the United Kingdom (n=45.854) and Portugal (n= 3.122). Socio-demographic, echographic and laboratory parameters were evaluated, and combined screening performance indicators were calculated. The analytical run of serum biochemical tests (PAPP-A and ß-hCG) was held at the Brahms Kryptor and in Delfia Xpress 6000. Comparisons between autoimmune group and non-autoimmune group were made. Results: Relating to population characteristics, the autoimmune group had significantly diferente values in the variables maternal age and gestational age. Comparing the groups with and without autoimmune disease, it was noted that there is an elevation of the MoM’s of free ß-hCG levels in pregnant women with autoimmune disease, particularly in cases of systemic lupus erythematosus. Conclusions: The results obtained reinforce the indication of FMF certified combined screening in pregnant women with autoimmune diseases, notably to the patients with SLE; However, correction factors should be calculated and entered in the risk algorithm, in order to avoid the rise in the number of false positive results, and consequently the over-use of invasive methods.
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Forty voluntary blood donors from two different blood banks in Havana, Cuba, who were repeatedly reactive on the routine screening of antibodies to hepatitis C virus, by Umelisa HCV test, were analyzed for the presence of HCV RNA using a nested PCR assay of the HCV 5' untranslated region, Umelosa HCV qualitative. Sera from 45 patients of a specialized gastroenterology consultation, positive to Umelisa HCV, were also assayed with the Umelosa HCV qualitative, to establish their condition related to the presence of HCV RNA previously to the indication of a treatment or after three, six or twelve months of antiviral therapy. Serum HCV-RNA was detected in 21/40 (52.5%) donors who had repeatedly positive ELISA results, confirming the HCV infection for them. In specialized consultation HCV-RNA was detected by PCR analysis in 30/45 (66%) analyzed sera.