991 resultados para diagnostic biomarkers


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Anaerobic methane-oxidizing microbial communities in sediments at cold methane seeps are important factors in controlling methane emission to the ocean and atmosphere. Here, we investigated the distribution and carbon isotopic signature of specific biomarkers derived from anaerobic methanotrophic archaea (ANME groups) and sulphate-reducing bacteria (SRB) responsible for the anaerobic oxidation of methane (AOM) at different cold seep provinces of Hydrate Ridge, Cascadia margin. The special focus was on their relation to in situ cell abundances and methane turnover. In general, maxima in biomarker abundances and minima in carbon isotope signatures correlated with maxima in AOM and sulphate reduction as well as with consortium biomass. We found ANME-2a/DSS aggregates associated with high abundances of sn-2,3-di-O-isoprenoidal glycerol ethers (archaeol, sn-2-hydroxyarchaeol) and specific bacterial fatty acids (C16:1omega5c, cyC17:0omega5,6) as well as with high methane fluxes (Beggiatoa site). The low to medium flux site (Calyptogena field) was dominated by ANME-2c/DSS aggregates and contained less of both compound classes but more of AOM-related glycerol dialkyl glycerol tetraethers (GDGTs). ANME-1 archaea dominated deeper sediment horizons at the Calyptogena field where sn-1,2-di-O-alkyl glycerol ethers (DAGEs), archaeol, methyl-branched fatty acids (ai-C15:0, i-C16:0, ai-C17:0), and diagnostic GDGTs were prevailing. AOM-specific bacterial and archaeal biomarkers in these sediment strata generally revealed very similar d13C-values of around -100 per mill. In ANME-2-dominated sediment sections, archaeal biomarkers were even more 13C-depleted (down to -120 per mill), whereas bacterial biomarkers were found to be likewise 13C-depleted as in ANME-1-dominated sediment layers (d13C: -100 per mill). The zero flux site (Acharax field), containing only a few numbers of ANME-2/DSS aggregates, however, provided no specific biomarker pattern. Deeper sediment sections (below 20 cm sediment depth) from Beggiatoa covered areas which included solid layers of methane gas hydrates contained ANME-2/DSS typical biomarkers showing subsurface peaks combined with negative shifts in carbon isotopic compositions. The maxima were detected just above the hydrate layers, indicating that methane stored in the hydrates may be available for the microbial community. The observed variations in biomarker abundances and 13C-depletions are indicative of multiple environmental and physiological factors selecting for different AOM consortia (ANME-2a/DSS, ANME-2c/DSS, ANME-1) along horizontal and vertical gradients of cold seep settings.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This study investigates organic-rich sedimentary sequences deposited during the early Aptian Oceanic Anoxic Event (OAE1a) at Sites 1207 and 1213 on Shatsky Rise (ODP Leg 198) in the west-central Pacific. Biomarker analyses provide evidence of the algal and bacterial origin of organic matter (OM) in these sediments where the abundance of steroidal components, particularly sterenes and sterones, suggests that the OM includes major contributions from eukaryotic sources in an environment characterized by high phytoplankton productivity. The presence of alkenones at Site 1213B is diagnostic of OM derived from representatives of haptophyte algae among the calcareous nannoplankton and their d13C values (average -31.6 per mil) are consistent with those expected during elevated pCO2. The occurrence and prominence of 2b-methylhopanes and 2b-methylhopanones indicates significant contributions to the OM from cyanobacteria, which are also likely contributors of hopanoids based on their d13C compositions. These biomarker data suggest that oceanic conditions, perhaps nitrate- or iron-limited, were conducive to cyanobacteria production during OAE1a, which appears to distinguish this event from other Cretaceous OAE.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The identification of biomarkers capable of providing a reliable molecular diagnostic test for prostate cancer (PCa) is highly desirabie clinically. We describe here 4 biomarkers, UDP-N-Acetyl-alpha-D-galactosamine transferase (GalNAc-T3; not previously associated with PCa), PSMA, Hepsin and DD3/PCA3, which, in combination, distinguish prostate cancer from benign prostate hyperplasia (BPH). GalNAc-T3 was identified as overexpressed in PCa tissues by microarray analysis, confirmed by quantitative real-time PCR and shown immunohistochemically to be localised to prostate epithelial cells with higher expression in malignant cells. Real-time quantitative PCR analysis across 21 PCa and 34 BPH tissues showed 4.6-fold overexpression of GalNAc-T3 (p = 0.005). The noncoding mRNA (DD3/PCA3) was overexpressed 140-fold (p = 0.007) in the cancer samples compared to BPH tissues. Hepsin was overexpressed 21-fold (p = 0.049, whereas the overexpression for PSMA was 66-fold (p = 0.047). When the gene expression data for these 4 biomarkers was combined in a logistic regression model, a predictive index was obtained that distinguished 100% of the PCa samples from all of the BPH samples. Therefore, combining these genes in a real-time PCR assay represents a powerful new approach to diagnosing PCa by molecular profiling. (c) 2005 Wiley-Liss, Inc.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We have carried out a discovery proteomics investigation aimed at identifying disease biomarkers present in saliva, and, more specifically, early biomarkers of inflammation. The proteomic characterization of saliva is possible due to the straightforward and non-invasive sample collection that allows repetitive analyses for pharmacokinetic studies. These advantages are particularly relevant in the case of newborn patients. The study was carried out with samples collected during the first 48 hours of life of the newborns according to an approved Ethic Committee procedure. In particular, the salivary samples were collected from healthy and infected (n=1) newborns. Proteins were extracted through cycles of sonication, precipitated in ice cold acetone, resuspended and resolved by 2D-electrophoresis. MALDI TOF/TOF mass spectrometry analysis was performed for each spot obtaining the proteins’ identifications. Then we compared healthy newborn salivary proteome and an infected newborn salivary proteome in order to investigate proteins differently expressed in inflammatory condition. In particular the protein alpha-1-antitrypsin (A1AT), correlated with inflammation, was detected differently expressed in the infected newborn saliva. Therefore, in the second part of the project we aimed to develop a robust LC-MS based method that identifies and quantifies this inflammatory protein within saliva that might represent the first relevant step to diagnose a condition of inflammation with a no-invasive assay. The same LC-MS method is also useful to investigate the presence of the F allelic variant of the A1AT in biological samples, which is correlated with the onset of pulmonary diseases. In the last part of the work we analysed newborn saliva samples in order to investigate how phospholipids and mediators of inflammation (eicosanoids) are subject to variations under inflammatory conditions and a trend was observed in lysophosphatidylcholines composition according to the inflammatory conditions.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

An important aspect of managing chronic liver disease is assessing for evidence of fibrosis. Historically, this has been accomplished using liver biopsy, which is an invasive procedure associated with risk for complications and significant sampling and observer error, limiting the accuracy for determination of fibrosis stage. Hence, several serum biomarkers and imaging methods for noninvasive assessment of liver fibrosis have been developed. In this article, we review the current literature on an important noninvasive imaging modality to measure tissue elastography (FibroScan(®)). This ultrasound-based technique is now increasingly available in many countries and has been shown to be a reliable and safe noninvasive means of assessing disease severity in chronic liver disease of varying etiology.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background At present, we do not have any biological tests which can contribute towards a diagnosis of depression. Neuroimaging measures have shown some potential as biomarkers for diagnosis. However, participants have generally been from the same ethnic background while the applicability of a biomarker would require replication in individuals of diverse ethnicities. Aims We sought to examine the diagnostic potential of the structural neuroanatomy of depression in a sample of a wide ethnic diversity. Method Structural magnetic resonance imaging (MRI) scans were obtained from 23 patients with major depressive disorder in an acute depressive episode (mean age: 39.8 years) and 20 matched healthy volunteers (mean age: 38.8 years). Participants were of Asian, African and Caucasian ethnicity recruited from the general community. Results Structural neuroanatomy combining white and grey matter distinguished patients from controls at the highest accuracy of 81% with the most stable pattern being at around 70%. A widespread network encompassing frontal, parietal, occipital and cerebellar regions contributed towards diagnostic classification. Conclusions These findings provide an important step in the development of potential neuroimaging-based tools for diagnosis as they demonstrate that the identification of depression is feasible within a multi-ethnic group from the community. Declaration of interests C.H.Y.F. has held recent research grants from Eli Lilly and Company and GlaxoSmithKline. L.M. is a former employee and stockholder of Eli Lilly and Company.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Invasive candidiasis (IC) is an opportunistic systemic mycosis caused by Candida species (commonly Candida albicans) that continues to pose a significant public health problem worldwide. Despite great advances in antifungal therapy and changes in clinical practices, IC remains a major infectious cause of morbidity and mortality in severely immunocompromised or critically ill patients, and further accounts for substantial healthcare costs. Its impact on patient clinical outcome and economic burden could be ameliorated by timely initiation of appropriate antifungal therapy. However, early detection of IC is extremely difficult because of its unspecific clinical signs and symptoms, and the inadequate accuracy and time delay of the currently available diagnostic or risk stratification methods. In consequence, the diagnosis of IC is often attained in advanced stages of infection (leading to delayed therapeutic interventions and ensuing poor clinical outcomes) or, unfortunately, at autopsy. In addition to the difficulties encountered in diagnosing IC at an early stage, the initial therapeutic decision-making process is also hindered by the insufficient accuracy of the currently available tools for predicting clinical outcomes in individual IC patients at presentation. Therefore, it is not surprising that clinicians are generally unable to early detect IC, and identify those IC patients who are most likely to suffer fatal clinical outcomes and may benefit from more personalized therapeutic strategies at presentation. Better diagnostic and prognostic biomarkers for IC are thus needed to improve the clinical management of this life-threatening and costly opportunistic fungal infection...

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Tese de Doutoramento em Ciências Veterinárias na Especialidade de Ciências Biológicas e Biomédicas

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Biomarkers are nowadays essential tools to be one step ahead for fighting disease, enabling an enhanced focus on disease prevention and on the probability of its occurrence. Research in a multidisciplinary approach has been an important step towards the repeated discovery of new biomarkers. Biomarkers are defined as biochemical measurable indicators of the presence of disease or as indicators for monitoring disease progression. Currently, biomarkers have been used in several domains such as oncology, neurology, cardiovascular, inflammatory and respiratory disease, and several endocrinopathies. Bridging biomarkers in a One Health perspective has been proven useful in almost all of these domains. In oncology, humans and animals are found to be subject to the same environmental and genetic predisposing factors: examples include the existence of mutations in BR-CA1 gene predisposing to breast cancer, both in human and dogs, with increased prevalence in certain dog breeds and human ethnic groups. Also, breast feeding frequency and duration has been related to a decreased risk of breast cancer in women and bitches. When it comes to infectious diseases, this parallelism is prone to be even more important, for as much as 75% of all emerging diseases are believed to be zoonotic. Examples of successful use of biomarkers have been found in several zoonotic diseases such as Ebola, dengue, leptospirosis or West Nile virus infections. Acute Phase Proteins (APPs) have been used for quite some time as biomarkers of inflammatory conditions. These have been used in human health but also in the veterinary field such as in mastitis evaluation and PRRS (porcine respiratory and reproductive syndrome) diagnosis. Advantages rely on the fact that these biomarkers can be much easier to assess than other conventional disease diagnostic approaches (example: measured in easy to collect saliva samples). Another domain in which biomarkers have been essential is food safety: the possibility to measure exposure to chemical contaminants or other biohazards present in the food chain, which are sometimes analytical challenges due to their low bioavailability in body fluids, is nowadays a major breakthrough. Finally, biomarkers are considered the key to provide more personalized therapies, with more efficient outcomes and fewer side effects. This approach is expected to be the correct path to follow also in veterinary medicine, in the near future.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The aim of this work was to investigate novel diagnostic and prognostic tools, postoperative treatments and epidemiologic factors impacting the outcome of surgical cases of colic. To make a more accurate diagnosis and establish a prognosis, several biomarkers have been investigated in colic patients. In this study we evaluated peritoneal PCT and blood ADMA and SDMA in SIRS positive and negative colic patients to be used as prognostic biomarkers. Our results highlighted the limits of these biomarkers in detection and the lack of specificity. In fact PCT was not detectable and even if ADMA and SDMA significantly increased in colic horses, they are not diagnostic nor prognostic markers for SIRS. Fluid therapy has been described to be crucial for the outcome of colic patients, nevertheless no guidelines have been established. Overhydration was the common practice in post surgical management. We compared cases with an extended fluid therapy protocol and cases with a restricted protocol. Results showed that survival rate and postoperative complications were similar between the groups, despite costs being significantly lower in the restricted group. The possible correlation between intestinal microbiota and colics has gained interest. In this study, cecal and colonic content from horses undergoing laparotomy were collected, and the microbiota analized. Results showed some differences in microbiota between discharged and non discharged patients, and between strangulating and non strangulating types of colic, that might suggest some influence of hind gut microbiota on the disease. A multicentric study involving three veterinary teaching hospitals on the italian territory was conducted investigating factors affecting postoperative survival and complications in colics. Results showed that the influence of age, PCV, TPP, blood lactate, reflux, type of disease, type of lesion, presence of anastomosis, duration of surgery and surgeons, were in line with literature. Amount of crystalloids used could affected the outcome.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In the Era of precision medicine and big medical data sharing, it is necessary to solve the work-flow of digital radiological big data in a productive and effective way. In particular, nowadays, it is possible to extract information “hidden” in digital images, in order to create diagnostic algorithms helping clinicians to set up more personalized therapies, which are in particular targets of modern oncological medicine. Digital images generated by the patient have a “texture” structure that is not visible but encrypted; it is “hidden” because it cannot be recognized by sight alone. Thanks to artificial intelligence, pre- and post-processing software and generation of mathematical calculation algorithms, we could perform a classification based on non-visible data contained in radiological images. Being able to calculate the volume of tissue body composition could lead to creating clasterized classes of patients inserted in standard morphological reference tables, based on human anatomy distinguished by gender and age, and maybe in future also by race. Furthermore, the branch of “morpho-radiology" is a useful modality to solve problems regarding personalized therapies, which is particularly needed in the oncological field. Actually oncological therapies are no longer based on generic drugs but on target personalized therapy. The lack of gender and age therapies table could be filled thanks to morpho-radiology data analysis application.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this study was to assess the efficacy and reproducibility of the cytologic diagnosis of salivary gland tumors (SGTs) using fine-needle aspiration cytology (FNAC). The study aimed to determine diagnostic accuracy, sensitivity, and specificity and to evaluate the extent of interobserver agreement. We retrospectively evaluated SGTs from the files of the Division of Pathology at the Clinics Hospital of São Paulo and Piracicaba Dental School between 2000 and 2006. We performed cytohistologic correlation in 182 SGTs. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were 94%, 100%, 100%, 100%, and 99%, respectively. The interobserver cytologic reproducibility showed significant statistical concordance (P < .0001). FNAC is an effective tool for performing a reliable preoperative diagnosis in SGTs and shows high diagnostic accuracy and consistent interobserver reproducibility. Further FNAC studies analyzing large samples of malignant SGTs and reactive salivary lesions are needed to confirm their accuracy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim was to describe the outcome of neonatal hearing screening (NHS) and audiological diagnosis in neonates in the NICU. The sample was divided into Group I: neonates who underwent NHS in one step and Group II: neonates who underwent a test and retest NHS. NHS procedure was automated auditory brainstem response. NHS was performed in 82.1% of surviving neonates. For GI, referral rate was 18.6% and false-positive was 62.2% (normal hearing in the diagnostic stage). In GII, with retest, referral rate dropped to 4.1% and false-positive to 12.5%. Sensorineural hearing loss was found in 13.2% of infants and conductive in 26.4% of cases. There was one case of auditory neuropathy spectrum (1.9%). Dropout rate in whole process was 21.7% for GI and 24.03% for GII. We concluded that it was not possible to perform universal NHS in the studied sample or, in many cases, to apply it within the first month of life. Retest reduced failure and false-positive rate and did not increase evasion, indicating that it is a recommendable step in NHS programs in the NICU. The incidence of hearing loss was 2.9%, considering sensorineural hearing loss (0.91%), conductive (1.83%) and auditory neuropathy spectrum (0.19%).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To assess the effects of a soy dietary supplement on the main biomarkers of cardiovascular health in postmenopausal women compared with the effects of low-dose hormone therapy (HT) and placebo. Double-blind, randomized and controlled intention-to-treat trial. Sixty healthy postmenopausal women, aged 40-60 years, 4.1 years mean time since menopause were recruited and randomly assigned to 3 groups: a soy dietary supplement group (isoflavone 90mg), a low-dose HT group (estradiol 1 mg plus noretisterone 0.5 mg) and a placebo group. Lipid profile, glucose level, body mass index, blood pressure and abdominal/hip ratio were evaluated in all the participants at baseline and after 16 weeks. Statistical analyses were performed using the χ2 test, Fisher's exact test, Kruskal-Wallis non-parametric test, analysis of variance (ANOVA), paired Student's t-test and Wilcoxon test. After a 16-week intervention period, total cholesterol decreased 11.3% and LDL-cholesterol decreased 18.6% in the HT group, but both did not change in the soy dietary supplement and placebo groups. Values for triglycerides, HDL-cholesterol, glucose level, body mass index, blood pressure and abdominal/hip ratio did not change over time in any of the three groups. The use of dietary soy supplement did not show any significant favorable effect on cardiovascular health biomarkers compared with HT. The trial is registered at the Brazilian Clinical Trials Registry (Registro Brasileiro de Ensaios Clínicos - ReBEC), number RBR-76mm75.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The search for an Alzheimer's disease (AD) biomarker is one of the most relevant contemporary research topics due to the high prevalence and social costs of the disease. Functional connectivity (FC) of the default mode network (DMN) is a plausible candidate for such a biomarker. We evaluated 22 patients with mild AD and 26 age- and gender-matched healthy controls. All subjects underwent resting functional magnetic resonance imaging (fMRI) in a 3.0 T scanner. To identify the DMN, seed-based FC of the posterior cingulate was calculated. We also measured the sensitivity/specificity of the method, and verified a correlation with cognitive performance. We found a significant difference between patients with mild AD and controls in average z-scores: DMN, whole cortical positive (WCP) and absolute values. DMN individual values showed a sensitivity of 77.3% and specificity of 70%. DMN and WCP values were correlated to global cognition and episodic memory performance. We showed that individual measures of DMN connectivity could be considered a promising method to differentiate AD, even at an early phase, from normal aging. Further studies with larger numbers of participants, as well as validation of normal values, are needed for more definitive conclusions.