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Frontiers in Aging Neuroscience 2021Alzheimer's disease (AD) is characterized by specific alterations of brain DNA methylation (DNAm) patterns. Age and sex, two major risk factors for AD, are also known to...
Alzheimer's disease (AD) is characterized by specific alterations of brain DNA methylation (DNAm) patterns. Age and sex, two major risk factors for AD, are also known to largely affect the epigenetic profiles in brain, but their contribution to AD-associated DNAm changes has been poorly investigated. In this study we considered publicly available DNAm datasets of four brain regions (temporal, frontal, entorhinal cortex, and cerebellum) from healthy adult subjects and AD patients, and performed a meta-analysis to identify sex-, age-, and AD-associated epigenetic profiles. In one of these datasets it was also possible to distinguish 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) profiles. We showed that DNAm differences between males and females tend to be shared between the four brain regions, while aging differently affects cortical regions compared to cerebellum. We found that the proportion of sex-dependent probes whose methylation is modified also during aging is higher than expected, but that differences between males and females tend to be maintained, with only a few probes showing age-by-sex interaction. We did not find significant overlaps between AD- and sex-associated probes, nor disease-by-sex interaction effects. On the contrary, we found that AD-related epigenetic modifications are significantly enriched in probes whose DNAm varies with age and that there is a high concordance between the direction of changes (hyper or hypo-methylation) in aging and AD, supporting accelerated epigenetic aging in the disease. In summary, our results suggest that age-associated DNAm patterns concur to the epigenetic deregulation observed in AD, providing new insights on how advanced age enables neurodegeneration.
PubMed: 33790779
DOI: 10.3389/fnagi.2021.639428 -
BMC Cancer Oct 2020DNA methylation is a potential biomarker for early detection of breast cancer. However, robust evidence of a prospective relationship between DNA methylation patterns...
BACKGROUND
DNA methylation is a potential biomarker for early detection of breast cancer. However, robust evidence of a prospective relationship between DNA methylation patterns and breast cancer risk is still lacking. The objective of this study is to provide a systematic analysis of the findings of epigenome-wide DNA methylation studies on breast cancer risk, in light of their methodological strengths and weaknesses.
METHODS
We searched major databases (MEDLINE, EMBASE, Web of Science, CENTRAL) from inception up to 30th June 2019, for observational or intervention studies investigating the association between epigenome-wide DNA methylation (using the HM450k or EPIC BeadChip), measured in any type of human sample, and breast cancer risk. A pre-established protocol was drawn up following the Cochrane Reviews rigorous methodology. Study selection, data abstraction, and risk of bias assessment were performed by at least two investigators. A qualitative synthesis and systematic comparison of the strengths and weaknesses of studies was performed.
RESULTS
Overall, 20 studies using the HM450k BeadChip were included, 17 of which had measured blood-derived DNA methylation. There was a consistent trend toward an association of global blood-derived DNA hypomethylation and higher epigenetic age with higher risk of breast cancer. The strength of associations was modest for global hypomethylation and relatively weak for most of epigenetic age algorithms. Differences in length of follow-up periods may have influenced the ability to detect associations, as studies reporting follow-up periods shorter than 10 years were more likely to observe an association with global DNA methylation. Probe-wise differential methylation analyses identified between one and 806 differentially methylated CpGs positions in 10 studies. None of the identified differentially methylated sites overlapped between studies. Three studies used breast tissue DNA and suffered major methodological issues that precludes any conclusion. Overall risk of bias was critical mainly because of incomplete control of confounding. Important issues relative to data preprocessing could have limited the consistency of results.
CONCLUSIONS
Global DNA methylation may be a short-term predictor of breast cancer risk. Further studies with rigorous methodology are needed to determine spatial distribution of DNA hypomethylation and identify differentially methylated sites associated with risk of breast cancer.
PROSPERO REGISTRATION NUMBER
CRD42020147244.
Topics: Biomarkers, Tumor; Breast Neoplasms; DNA Methylation; Epigenesis, Genetic; Female; Gene Expression Regulation, Neoplastic; Genome-Wide Association Study; Humans; Prognosis
PubMed: 33129307
DOI: 10.1186/s12885-020-07543-4 -
The Science of the Total Environment Feb 2021Fish environmental DNA (eDNA) studies have made substantial progress during the past decade, and significant advances in monitoring fishes have been gained by taking... (Review)
Review
Fish environmental DNA (eDNA) studies have made substantial progress during the past decade, and significant advances in monitoring fishes have been gained by taking advantage of this technology. Although a number of reviews concerning eDNA are available and some recent fish eDNA reviews focused on fisheries or standard method have been published, a systematic review of methodology of fish eDNA and its applications in ecology and environment has not yet been published. To our knowledge, this is the first review of fish eDNA for solving ecological and environmental issues. First, the most comprehensive literature analysis of fish eDNA was presented and analyzed. Then, we systematically discuss the relevant experiments and analyses of fish eDNA, and infers that standard workflow is on the way to consensus. We additionally provide reference sequence databases and the primers used to amplify the reference sequences or detecting fish eDNA. The abiotic and biotic conditions affecting fish eDNA persistence are also summarized in a schematic diagram. Subsequently, we focus on the major achievements of fish eDNA in ecology and environment. We additionally highlight the exciting new tools, including in situ autonomous monitoring devices, CRISPR nucleic acid detection technology, and meta-omics technology for fish eDNA detection in future. Ultimately, methodology of fish eDNA will provide a wholly new paradigm for conservation actions of fishes, ecological and environmental management at a global scale.
Topics: Animals; Biodiversity; DNA Primers; Environmental Monitoring; Fisheries; Fishes
PubMed: 33059148
DOI: 10.1016/j.scitotenv.2020.142622 -
Infectious Agents and Cancer 2020Genital infection with certain types of Human papillomavirus (HPV) is a major cause of cervical cancer globally. For early detection of premalignant dysplasia, evidences... (Review)
Review
BACKGROUND
Genital infection with certain types of Human papillomavirus (HPV) is a major cause of cervical cancer globally. For early detection of premalignant dysplasia, evidences are coming out on the usefulness of HPV E6/E7 mRNA test as a potential tool compared with cytology and HPV DNA testing. Taking into account shortage of compiled data on this field, the aim of this systematic review was to describe the latest diagnostic performance of HPV E6/E7 mRNA testing to detect high grade cervical lesions (CIN2+) where by histology was taken as a gold standard.
METHODS
Articles published in English were systematically searched using key words from PubMed/Medline and SCOPUS. In addition, Google Scholar and the Google database were searched manually for grey literature. Two reviewers independently assessed study eligibility, risk of bias and extracted the data. We performed a descriptive presentation of the performance of E6/E7 mRNA test (in terms of sensitivity, specificity, negative and positive predictive values) for the detection of CIN2 + .
RESULTS
Out of 231 applicable citations, we have included 29 articles that included a total of 23,576 study participants (age range, 15-84 years) who had different cervical pathologies. Among the participants who had cervical histology, the proportion of CIN2+ was between 10.6 and 90.6%. Using histology as a gold standard, 11 studies evaluated the PreTect HPV Proofer, 7 studies evaluated the APTIMA HPV assay (Gen-Probe) and 6 studies evaluated the Quantivirus® HPV assay. The diagnostic performance of these three most common mRNA testing tools to detect CIN2+ was; 1) PreTect Proofer; median sensitivity 83%, specificity 73%, PPV 70 and NPV 88.9%. 2) APTIMA assay; median sensitivity 91.4%, specificity 46.2%, PPV 34.3% and NPV 96.3%. 3) Quantivirus®: median sensitivity 86.1%, specificity 54.6%, PPV 54.3% and NPV was at 89.3%. Further, the area under the receiver operating characteristics (AU-ROC) curve varied between 63.8 and 90.9%.
CONCLUSIONS
The reported diagnostic accuracy implies that HPV mRNA based tests possess diagnostic relevance to detect CIN2+ and could potentially be considered in areas where there is no histology facility. Further studies including its cost should be considered.
PubMed: 32047531
DOI: 10.1186/s13027-020-0278-x -
Experimental Parasitology Dec 2019Studies of the primers that were designed to detect New World Leishmania were systematically reviewed to report the characteristics of each target, detection limit,...
Studies of the primers that were designed to detect New World Leishmania were systematically reviewed to report the characteristics of each target, detection limit, specificity of the primers designed and diagnostic sensibility. The papers identified in the databases PubMed and Web of Science involved 50 studies. Minicircle is the most applied target in molecular research for diagnosis, due to its high sensitivity in detecting Leishmania in different clinical samples, a characteristic that can be partially attributed to the higher number of copies of the minicircle per cell. The other molecular targets shown in this review were less sensitive to diagnostic use because of the lower number of copies of the target gene per cell, but more specific for identification of the subgenus and/or species. The choice of the best target is an important step towards the result of the research. The target allows the design of primers that are specific to the genus, subgenus or a particular species and also imparts sensitivity to the method for diagnosis. The findings of this systematic review provide the advantages and disadvantages of the main molecular targets and primers designed for New World Leishmania, offering information so that the researcher can choose the PCR system best suited to their research need. This is a timely and extremely thorough review of the primers designed for New World Leishmania.
Topics: DNA Primers; DNA, Protozoan; Humans; Leishmania; Leishmaniasis, Cutaneous; Limit of Detection; Polymerase Chain Reaction; Sensitivity and Specificity
PubMed: 31605671
DOI: 10.1016/j.exppara.2019.107773 -
Journal of Diabetes Research 2017The role of nesfatin-1 in glucose homeostasis has been investigated previously. However, although numerous studies have examined the relationships between circulating... (Meta-Analysis)
Meta-Analysis Review
The role of nesfatin-1 in glucose homeostasis has been investigated previously. However, although numerous studies have examined the relationships between circulating nesfatin-1 levels and type 2 diabetes, the conclusions are contradictory. We aimed to probe the relationship between circulating nesfatin-1 levels and type 2 diabetes by meta-analysis. Seven studies including 328 type 2 diabetes patients and 294 control subjects were included. Although there was no obvious difference in circulating nesfatin-1 levels between patients with type 2 diabetes and the control group (MD = -0.04; 95% CI = -0.32 to -0.23), subgroup analysis showed higher nesfatin-1 levels in newly diagnosed type 2 diabetes patients (MD = 0.59; 95% CI = 0.45 to 0.74) and significantly lower nesfatin-1 levels in type 2 diabetes patients receiving antidiabetic treatment (MD = -0.26; 95% CI = -0.33 to -0.20). In conclusion, the analysis supports a relationship between circulating nesfatin-1 levels and type 2 diabetes, where newly diagnosed type 2 diabetes was associated with an elevated Nesfatin-1 level, and type 2 diabetes patients receiving antidiabetic treatment showed lower circulating nesfatin-1 levels.
Topics: Biomarkers; Calcium-Binding Proteins; DNA-Binding Proteins; Diabetes Mellitus, Type 2; Disease Progression; Down-Regulation; Humans; Hypoglycemic Agents; Nerve Tissue Proteins; Nucleobindins; Reproducibility of Results; Up-Regulation
PubMed: 29445751
DOI: 10.1155/2017/7687098 -
Journal of Ovarian Research Mar 2017Mature cystic teratomas are usually found in the ovaries. They are bilateral in 10 to 15% of cases and multiple cystic teratomas may be present in one ovary. The aim of... (Review)
Review
BACKGROUND
Mature cystic teratomas are usually found in the ovaries. They are bilateral in 10 to 15% of cases and multiple cystic teratomas may be present in one ovary. The aim of this study is to clarify if development of mature cystic teratomas of the ovaries in a single host is metachronous or due to autoimplant or recurrence.
CASE PRESENTATION
We report a woman with bilateral mature cystic teratomas of the ovaries. DNA profiles of these teratomas were investigated via short tandem repeat (STR) analysis and methylation statuses were determined via methylation sensitive multiplex ligation-dependent probe amplification methods. The results showed that the cystic teratomas originated from different stages of oogonia or primary oocyte before germinal vesicle stage failure of meiosis I in female gametogenesis. Potentially relevant literature was searched in PubMed database. Cases of bilateral or multiple mature cystic teratomas of the ovaries were analyzed. To date, there has been no reported case of multiple mature cystic teratomas in which clarification of the origin was achieved using molecular genetic methods.
CONCLUSIONS
The results of this case study provide evidence of metachronous development of mature cystic teratomas of the ovaries and may serve as a reference in the management of patients following laparoscopic cystectomy.
Topics: Adult; DNA Copy Number Variations; DNA Methylation; Female; Genetic Loci; Humans; Loss of Heterozygosity; Microsatellite Repeats; Neoplasm Grading; Neoplasms, Second Primary; Ovarian Neoplasms; Sequence Analysis, DNA; Teratoma
PubMed: 28288660
DOI: 10.1186/s13048-017-0313-8 -
The European Respiratory Journal Jan 2017Only 25% of multidrug-resistant tuberculosis (MDR-TB) cases are currently diagnosed. Line probe assays (LPAs) enable rapid drug-susceptibility testing for rifampicin... (Meta-Analysis)
Meta-Analysis Review
Only 25% of multidrug-resistant tuberculosis (MDR-TB) cases are currently diagnosed. Line probe assays (LPAs) enable rapid drug-susceptibility testing for rifampicin (RIF) and isoniazid (INH) resistance and Mycobacterium tuberculosis detection. Genotype MTBDRplusV1 was WHO-endorsed in 2008 but newer LPAs have since been developed.This systematic review evaluated three LPAs: Hain Genotype MTBDRplusV1, MTBDRplusV2 and Nipro NTM+MDRTB. Study quality was assessed with QUADAS-2. Bivariate random-effects meta-analyses were performed for direct and indirect testing. Results for RIF and INH resistance were compared to phenotypic and composite (incorporating sequencing) reference standards. M. tuberculosis detection results were compared to culture.74 unique studies were included. For RIF resistance (21 225 samples), pooled sensitivity and specificity (with 95% confidence intervals) were 96.7% (95.6-97.5%) and 98.8% (98.2-99.2%). For INH resistance (20 954 samples), pooled sensitivity and specificity were 90.2% (88.2-91.9%) and 99.2% (98.7-99.5%). Results were similar for direct and indirect testing and across LPAs. Using a composite reference standard, specificity increased marginally. For M. tuberculosis detection (3451 samples), pooled sensitivity was 94% (89.4-99.4%) for smear-positive specimens and 44% (20.2-71.7%) for smear-negative specimens.In patients with pulmonary TB, LPAs have high sensitivity and specificity for RIF resistance and high specificity and good sensitivity for INH resistance. This meta-analysis provides evidence for policy and practice.
Topics: Antitubercular Agents; DNA Probes; Drug Resistance, Multiple, Bacterial; Humans; Isoniazid; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Nucleic Acid Amplification Techniques; Rifampin; Sensitivity and Specificity; Sputum; Tuberculosis, Multidrug-Resistant; Tuberculosis, Pulmonary
PubMed: 28100546
DOI: 10.1183/13993003.01075-2016 -
Journal of Voice : Official Journal of... Mar 2017The reported range of involvement of human papillomavirus (HPV) in laryngeal squamous cell carcinoma (SCC) is wide because of the methods used to detect HPV. (Review)
Review
OBJECTIVE
The reported range of involvement of human papillomavirus (HPV) in laryngeal squamous cell carcinoma (SCC) is wide because of the methods used to detect HPV.
DATA SOURCES
A computerized Medline study was carried out using the following as key words: "Papillomavirus Infections"[Mesh] and "Laryngeal Neoplasms"[Mesh].
MATERIALS AND METHODS
Studies that were included were written in English and reported results of HPV DNA with RNA in laryngeal SCC.
RESULTS
There were six reported HPV mRNA extraction. Among these studies, Lewis et al reported that out of the 31 cases analyzed, only 2 were HPV DNA+ and of these only 1 was mRNA HPV+ (3%). Halec et al reported 102 cases of which 32 were HPV DNA+ cases and of which only 6 were mRNA+ (5%). Chernock et al reported 76 cases of which 13 were HPV DNA+ cases and of which 4 were mRNA+ (5%). Masand et al reported 8 cases of which 1 was HPV DNA+ case and none was mRNA+. Gheit et al reported 43 cases of which 4 were HPV DNA+ cases and of which 2 were mRNA+ (4%). Castellsagné et al reported 1042 cases of which 59 were HPV DNA+ case and of which 51 were mRNA+ (4.8%) CONCLUSIONS: When determining the role of HPV in laryngeal SCC, evidence of HPV DNA warrants further examination for E6/E7 mRNA as simple assays such as p16 are nonspecific in laryngeal SCC. Further studies of HPV and its role in laryngeal SCC are warranted.
Topics: Blotting, Southern; Carcinoma, Squamous Cell; Cell Transformation, Viral; DNA Probes, HPV; DNA, Viral; Head and Neck Neoplasms; Human Papillomavirus DNA Tests; Humans; In Situ Hybridization; Laryngeal Neoplasms; Papillomaviridae; Papillomavirus E7 Proteins; Papillomavirus Infections; Polymerase Chain Reaction; Predictive Value of Tests; RNA, Messenger; RNA, Viral; Reproducibility of Results; Squamous Cell Carcinoma of Head and Neck
PubMed: 27613249
DOI: 10.1016/j.jvoice.2016.08.002 -
Health Technology Assessment... May 2015There is growing interest in the potential utility of real-time polymerase chain reaction (PCR) in diagnosing bloodstream infection by detecting pathogen... (Review)
Review
Rapid detection of health-care-associated bloodstream infection in critical care using multipathogen real-time polymerase chain reaction technology: a diagnostic accuracy study and systematic review.
BACKGROUND
There is growing interest in the potential utility of real-time polymerase chain reaction (PCR) in diagnosing bloodstream infection by detecting pathogen deoxyribonucleic acid (DNA) in blood samples within a few hours. SeptiFast (Roche Diagnostics GmBH, Mannheim, Germany) is a multipathogen probe-based system targeting ribosomal DNA sequences of bacteria and fungi. It detects and identifies the commonest pathogens causing bloodstream infection. As background to this study, we report a systematic review of Phase III diagnostic accuracy studies of SeptiFast, which reveals uncertainty about its likely clinical utility based on widespread evidence of deficiencies in study design and reporting with a high risk of bias.
OBJECTIVE
Determine the accuracy of SeptiFast real-time PCR for the detection of health-care-associated bloodstream infection, against standard microbiological culture.
DESIGN
Prospective multicentre Phase III clinical diagnostic accuracy study using the standards for the reporting of diagnostic accuracy studies criteria.
SETTING
Critical care departments within NHS hospitals in the north-west of England.
PARTICIPANTS
Adult patients requiring blood culture (BC) when developing new signs of systemic inflammation.
MAIN OUTCOME MEASURES
SeptiFast real-time PCR results at species/genus level compared with microbiological culture in association with independent adjudication of infection. Metrics of diagnostic accuracy were derived including sensitivity, specificity, likelihood ratios and predictive values, with their 95% confidence intervals (CIs). Latent class analysis was used to explore the diagnostic performance of culture as a reference standard.
RESULTS
Of 1006 new patient episodes of systemic inflammation in 853 patients, 922 (92%) met the inclusion criteria and provided sufficient information for analysis. Index test assay failure occurred on 69 (7%) occasions. Adult patients had been exposed to a median of 8 days (interquartile range 4-16 days) of hospital care, had high levels of organ support activities and recent antibiotic exposure. SeptiFast real-time PCR, when compared with culture-proven bloodstream infection at species/genus level, had better specificity (85.8%, 95% CI 83.3% to 88.1%) than sensitivity (50%, 95% CI 39.1% to 60.8%). When compared with pooled diagnostic metrics derived from our systematic review, our clinical study revealed lower test accuracy of SeptiFast real-time PCR, mainly as a result of low diagnostic sensitivity. There was a low prevalence of BC-proven pathogens in these patients (9.2%, 95% CI 7.4% to 11.2%) such that the post-test probabilities of both a positive (26.3%, 95% CI 19.8% to 33.7%) and a negative SeptiFast test (5.6%, 95% CI 4.1% to 7.4%) indicate the potential limitations of this technology in the diagnosis of bloodstream infection. However, latent class analysis indicates that BC has a low sensitivity, questioning its relevance as a reference test in this setting. Using this analysis approach, the sensitivity of the SeptiFast test was low but also appeared significantly better than BC. Blood samples identified as positive by either culture or SeptiFast real-time PCR were associated with a high probability (> 95%) of infection, indicating higher diagnostic rule-in utility than was apparent using conventional analyses of diagnostic accuracy.
CONCLUSION
SeptiFast real-time PCR on blood samples may have rapid rule-in utility for the diagnosis of health-care-associated bloodstream infection but the lack of sensitivity is a significant limiting factor. Innovations aimed at improved diagnostic sensitivity of real-time PCR in this setting are urgently required. Future work recommendations include technology developments to improve the efficiency of pathogen DNA extraction and the capacity to detect a much broader range of pathogens and drug resistance genes and the application of new statistical approaches able to more reliably assess test performance in situation where the reference standard (e.g. blood culture in the setting of high antimicrobial use) is prone to error.
STUDY REGISTRATION
The systematic review is registered as PROSPERO CRD42011001289.
FUNDING
The National Institute for Health Research Health Technology Assessment programme. Professor Daniel McAuley and Professor Gavin D Perkins contributed to the systematic review through their funded roles as codirectors of the Intensive Care Foundation (UK).
Topics: Bacteremia; Critical Care; Cross Infection; England; False Negative Reactions; False Positive Reactions; Humans; Prospective Studies; Real-Time Polymerase Chain Reaction; Sensitivity and Specificity; State Medicine; Technology Assessment, Biomedical; Time Factors
PubMed: 25961752
DOI: 10.3310/hta19350