153 resultados para Biomarker
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Introduction: Small for gestational age (SGA) is an important problem affecting 10% of pregnancies and is associated with significant perinatal morbidity. In about 80% of cases, a probable etiology or a major risk factor can be identified. But almost 20% of SGA cases are considered unexplained. The 60-kDa heat shock protein (HSP60) is a highly immunogenic protein whose synthesis is greatly upregulated under nonphysiological conditions. Bacterial and human HSP60 share a high degree of sequence homology, and immunity to conserved epitopes may result in development of autoimmunity following a bacterial infection. We hypothesized that unexplained SGA could be the consequence of immune sensitization to human HSP60. Methods: Unexplained SGA fetuses were identified by ultrasound biometry with normal Doppler velocimetry and with no detectable maternal or fetal abnormalities. Fetal sera were obtained by cordocentesis performed for a karyotype analysis in cases of unexplained SGA (study group) or for screening of Rhesus incompatibility (control group). Fetal sera were tested for HSP60 antigen and for IgG and IgM anti-HSP60 by ELISA as well as for other immune and hematological parameters. Results: Maternal parameters were similar between the 12 study cases and the 23 control cases. The mean gestational age at cordocentesis was 29 weeks. IgM anti-HSP60 was detected in 12 cases (100%) and in no controls (p < 0.00017), while IgG anti-HSP60 was detected in 7 cases (58%) and only 1 control (p < 0.001). Three of the 4 cases with the highest IgM antibody levels died. There were no differences in fetal serum levels of HSP60 antigen or other immune and hematological markers between the two groups. Conclusion: Fetuses with unexplained SGA are positive for IgM and IgG antibody to human HSP60 and the specific IgM antibody level is predictive of fetal mortality. Detection of these antibodies indicates that a placental perturbation and a fetal autoimmune reaction to HSP60 are associated with this developmental delay.
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Copeptin has been shown to increase in patients with sepsis, severe sepsis and septic shock. In the study herein described, copeptin was measured in a series of sepsis-related fatalities and control cases that underwent medico-legal investigations. No age-dependent differences in copeptin levels in either sepsis or control cases were observed. No correlation between copeptin concentrations and postmortem interval was identified in either group. Copeptin levels were significantly higher in sepsis cases. Moreover, copeptin concentrations in septic cases correlated with procalcitonin, C-reactive protein and interleukin 6 values. These preliminary findings seem to indicate that copeptin can be reliably measured in biological samples collected during postmortem investigations. These results also suggest that hemodynamic instability associated with sepsis and septic shock can be characterized by copeptin measurement also in the forensic casework.
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PURPOSE: The diagnosis of leptomeningeal metastases is usually confirmed by the finding of malignant cells by cytologic examination in the cerebrospinal fluid (CSF). More sensitive and specific cancer biomarkers may improve the detection of tumor cells in the CSF. Promoter methylation of the human telomerase reverse transcriptase (hTERT) gene characterizes most cancer cells. The aim of this study was to develop a sensitive method to detect hTERT methylation and to explore its use as a cancer biomarker in CSF. EXPERIMENTAL DESIGN: In 77 CSF specimens from 67 patients, hTERT promoter methylation was evaluated using real-time methylation-sensitive high-resolution melting (MS-HRM) and real-time TaqMan PCR and MS-HRM in a single-tube assay. RESULTS: Real-time MS-HRM assay was able to detect down to 1% hTERT-methylated DNA in a background of unmethylated DNA. PCR products were obtained from 90% (69/77) of CSF samples. No false positive hTERT was detected in the 21 non-neoplastic control cases, given to the method a specificity of 100%. The sensitivity of the real-time MS-HRM compared with the cytologic gold standard analysis was of 92% (11/12). Twenty-six CSFs from 22 patients with an hTERT-methylated primary tumor showed cytologic results suspicious for malignancy; in 17 (65%) of them, a diagnosis of leptomeningeal metastases could be confirmed by the hTERT methylation test. CONCLUSION: The hTERT real-time MS-HRM approach is fast, specific, sensitive, and could therefore become a valuable tool for diagnosis of leptomeningeal metastases as an adjunct to the traditional examination of CSF. Clin Cancer Res; 19(8); 2216-23. ©2013 AACR.
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Agricultural workers are exposed to folpet, but biomonitoring data are limited. Phthalimide (PI), phthalamic acid (PAA), and phthalic acid (PA) are the ring metabolites of this fungicide according to animal studies, but they have not yet been measured in human urine as metabolites of folpet, only PA as a metabolite of phthalates. The objective of this study was thus to develop a reliable gas chromatography-tandem mass spectrometry (GC-MS) method to quantify the sum of PI, PAA, and PA ring-metabolites of folpet in human urine. Briefly, the method consisted of adding p-methylhippuric acid as an internal standard, performing an acid hydrolysis at 100 °C to convert ring-metabolites into PA, purifying samples by ethyl acetate extraction, and derivatizing with N,O-bis(trimethylsilyl)trifluoro acetamide prior to GC-MS analysis. The method had a detection limit of 60.2 nmol/L (10 ng/mL); it was found to be accurate (mean recovery, 97%), precise (inter- and intra-day percentage relative standard deviations <13%), and with a good linearity (R (2) > 0.98). Validation was conducted using unexposed peoples urine spiked at concentrations ranging from 4.0 to 16.1 μmol/L, along with urine samples of volunteers dosed with folpet, and of exposed workers. The method proved to be (1) suitable and accurate to determine the kinetic profile of PA equivalents in the urine of volunteers orally and dermally administered folpet and (2) relevant for the biomonitoring of exposure in workers.
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Excessive alcohol consumption represents a major risk factor for morbidity and mortality. It is therefore indispensable to be able to detect at-risk drinking. Ethyl glucuronide (EtG) is a specific marker of alcohol consumption. The determination of ethyl glucuronide in urine or blood can be used to prove recent driving under the influence of alcohol, even if ethanol is no longer detectable. The commercialization of an EtG specific immunological assay now allows to obtain preliminary results rapidly and easily with satisfying sensitivity. Moreover, the detection of ethyl glucuronide in hair offers the opportunity to evaluate an alcohol consumption over a long period. The EtG concentration in hair is in correlation with the amount of ingested alcohol. Thus, the analysis of ethyl glucuronide can be used to monitor abstinence, to detect alcohol relapse and to identify at-risk drinkers. However, a cut off allowing to detect chronic alcohol abuser reliably still does not exist. Therefore, it is recommended to perform the analysis of ethyl glucuronide in complement to the existing blood markers. A study financed by the Swiss Foundation for Alcohol Research is actually conducted by the West Switzerland University Center of Legal Medicine in order to establish an objective cut-off.
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Many patients with malignant gliomas do not respond to alkylating agent chemotherapy. Alkylator resistance of glioma cells is mainly mediated by the DNA repair enzyme O(6)-methylguanine-DNA methyltransferase (MGMT). Epigenetic silencing of the MGMT gene by promoter methylation in glioma cells compromises this DNA repair mechanism and increases chemosensitivity. MGMT promoter methylation is, therefore, a strong prognostic biomarker in paediatric and adult patients with glioblastoma treated with temozolomide. Notably, elderly patients (>65-70 years) with glioblastoma whose tumours lack MGMT promoter methylation derive minimal benefit from such chemotherapy. Thus, MGMT promoter methylation status has become a frequently requested laboratory test in neuro-oncology. This Review presents current data on the prognostic and predictive relevance of MGMT testing, discusses clinical trials that have used MGMT status to select participants, evaluates known issues concerning the molecular testing procedure, and addresses the necessity for molecular-context-dependent interpretation of MGMT test results. Whether MGMT promoter methylation testing should be offered to all individuals with glioblastoma, or only to elderly patients and those in clinical trials, is also discussed. Justifications for withholding alkylating agent chemotherapy in patients with MGMT-unmethylated glioblastomas outside clinical trials, and the potential role for MGMT testing in other gliomas, are also discussed.
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Bacterial bioreporters have substantial potential for contaminant assessment but their real world application is currently impaired by a lack of sensitivity. Here, we exploit the bioconcentration of chemicals in the urine of animals to facilitate pollutant detection. The shore crab Carcinus maenas was exposed to the organic contaminant 2-hydroxybiphenyl, and urine was screened using an Escherichia coli-based luciferase gene (luxAB) reporter assay specific to this compound. Bioassay measurements differentiated between the original contaminant and its metabolites, quantifying bioconcentration factors of up to one hundred-fold in crab urine. Our results reveal the substantial potential of using bacterial bioreporter assays in real-time monitoring of biological matricesto determine exposure histories, with wide ranging potential for the in situ measurement of xenobiotics in risk assessments and epidemiology.
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PURPOSE: Rechallenge with temozolomide (TMZ) at first progression of glioblastoma after temozolomide chemoradiotherapy (TMZ/RT→TMZ) has been studied in retrospective and single-arm prospective studies, applying temozolomide continuously or using 7/14 or 21/28 days schedules. The DIRECTOR trial sought to show superiority of the 7/14 regimen. EXPERIMENTAL DESIGN: Patients with glioblastoma at first progression after TMZ/RT→TMZ and at least two maintenance temozolomide cycles were randomized to Arm A [one week on (120 mg/m(2) per day)/one week off] or Arm B [3 weeks on (80 mg/m(2) per day)/one week off]. The primary endpoint was median time-to-treatment failure (TTF) defined as progression, premature temozolomide discontinuation for toxicity, or death from any cause. O(6)-methylguanine DNA methyltransferase (MGMT) promoter methylation was prospectively assessed by methylation-specific PCR. RESULTS: Because of withdrawal of support, the trial was prematurely closed to accrual after 105 patients. There was a similar outcome in both arms for median TTF [A: 1.8 months; 95% confidence intervals (CI), 1.8-3.2 vs. B: 2.0 months; 95% CI, 1.8-3.5] and overall survival [A: 9.8 months (95% CI, 6.7-13.0) vs. B: 10.6 months (95% CI, 8.1-11.6)]. Median TTF in patients with MGMT-methylated tumors was 3.2 months (95% CI, 1.8-7.4) versus 1.8 months (95% CI, 1.8-2) in MGMT-unmethylated glioblastoma. Progression-free survival rates at 6 months (PFS-6) were 39.7% with versus 6.9% without MGMT promoter methylation. CONCLUSIONS: Temozolomide rechallenge is a treatment option for MGMT promoter-methylated recurrent glioblastoma. Alternative strategies need to be considered for patients with progressive glioblastoma without MGMT promoter methylation.
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OBJECTIVE: Blood-borne biomarkers reflecting atherosclerotic plaque burden have great potential to improve clinical management of atherosclerotic coronary artery disease and acute coronary syndrome (ACS). APPROACH AND RESULTS: Using data integration from gene expression profiling of coronary thrombi versus peripheral blood mononuclear cells and proteomic analysis of atherosclerotic plaque-derived secretomes versus healthy tissue secretomes, we identified fatty acid-binding protein 4 (FABP4) as a biomarker candidate for coronary artery disease. Its diagnostic and prognostic performance was validated in 3 different clinical settings: (1) in a cross-sectional cohort of patients with stable coronary artery disease, ACS, and healthy individuals (n=820), (2) in a nested case-control cohort of patients with ACS with 30-day follow-up (n=200), and (3) in a population-based nested case-control cohort of asymptomatic individuals with 5-year follow-up (n=414). Circulating FABP4 was marginally higher in patients with ST-segment-elevation myocardial infarction (24.9 ng/mL) compared with controls (23.4 ng/mL; P=0.01). However, elevated FABP4 was associated with adverse secondary cerebrovascular or cardiovascular events during 30-day follow-up after index ACS, independent of age, sex, renal function, and body mass index (odds ratio, 1.7; 95% confidence interval, 1.1-2.5; P=0.02). Circulating FABP4 predicted adverse events with similar prognostic performance as the GRACE in-hospital risk score or N-terminal pro-brain natriuretic peptide. Finally, no significant difference between baseline FABP4 was found in asymptomatic individuals with or without coronary events during 5-year follow-up. CONCLUSIONS: Circulating FABP4 may prove useful as a prognostic biomarker in risk stratification of patients with ACS.
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BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder characterized by numerous fluid-filled cysts that frequently result in end-stage renal disease. While promising treatment options are in advanced clinical development, early diagnosis and follow-up remain a major challenge. We therefore evaluated the diagnostic value of Fetuin-A as a new biomarker of ADPKD in human urine. RESULTS: We found that renal Fetuin-A levels are upregulated in both Pkd1 and Bicc1 mouse models of ADPKD. Measurement by ELISA revealed that urinary Fetuin-A levels were significantly higher in 66 ADPKD patients (17.5 ± 12.5 μg/mmol creatinine) compared to 17 healthy volunteers (8.5 ± 3.8 μg/mmol creatinine) or 50 control patients with renal diseases of other causes (6.2 ± 2.9 μg/mmol creatinine). Receiver operating characteristics (ROC) analysis of urinary Fetuin-A levels for ADPKD rendered an optimum cut-off value of 12.2 μg/mmol creatinine, corresponding to 94% of sensitivity and 60% of specificity (area under the curve 0.74 ; p = 0.0019). Furthermore, urinary Fetuin-A levels in ADPKD patients correlated with the degree of renal insufficiency and showed a significant increase in patients with preserved renal function followed for two years. CONCLUSIONS: Our findings establish urinary Fetuin-A as a sensitive biomarker of the progression of ADPKD. Further studies are required to examine the pathogenic mechanisms of elevated renal and urinary Fetuin-A in ADPKD.
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Autologous blood transfusion (ABT) is an efficient way to increase sport performance. It is also the most challenging doping method to detect. At present, individual follow-up of haematological variables via the athlete biological passport (ABP) is used to detect it. Quantification of a novel hepatic peptide called hepcidin may be a new alternative to detect ABT. In this prospective clinical trial, healthy subjects received a saline injection for the control phase, after which they donated blood that was stored and then transfused 36 days later. The impact of ABT on hepcidin as well as haematological parameters, iron metabolism, and inflammation markers was investigated. Blood transfusion had a particularly marked effect on hepcidin concentrations compared to the other biomarkers, which included haematological variables. Hepcidin concentrations increased significantly: 12 hr and 1 day after blood reinfusion, these concentrations rose by seven- and fourfold, respectively. No significant change was observed in the control phase. Hepcidin quantification is a cost-effective strategy that could be used in an "ironomics" strategy to improve the detection of ABT. Am. J. Hematol. 91:467-472, 2016. © 2016 Wiley Periodicals, Inc.