97 research outputs found
O-methylguanine-DNA methyltransferase (MGMT) mRNA expression predicts outcome in malignant glioma independent of MGMT promoter methylation
No full textBackground: We analyzed prospectively whether MGMT (O(6)-methylguanine-DNA methyltransferase) mRNA expression gains prognostic/predictive impact independent of MGMT promoter methylation in malignant glioma patients undergoing radiotherapy with concomitant and adjuvant temozolomide or temozolomide alone. As DNA-methyltransferases (DNMTs) are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells, we analyzed further, whether MGMT promoter methylation is associated with upregulation of DNMT expression.
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Abstract
Background
We analyzed prospectively whether MGMT (O6-methylguanine-DNA methyltransferase) mRNA expression gains prognostic/predictive impact independent of MGMT promoter methylation in malignant glioma patients undergoing radiotherapy with concomitant and adjuvant temozolomide or temozolomide alone. As DNA-methyltransferases (DNMTs) are the enzymes responsible for setting up and maintaining DNA methylation patterns in eukaryotic cells, we analyzed further, whether MGMT promoter methylation is associated with upregulation of DNMT expression.
Methodology/Principal Findings:
Adult patients with a histologically proven malignant astrocytoma (glioblastoma: N = 53, anaplastic astrocytoma: N = 10) were included. MGMT promoter methylation was determined by methylation-specific PCR (MSP) and sequencing analysis. Expression of MGMT and DNMTs mRNA were analysed by real-time qPCR. Prognostic factors were obtained from proportional hazards models. Correlation between MGMT mRNA expression and MGMT methylation status was validated using data from the Cancer Genome Atlas (TCGA) database (N = 229 glioblastomas). Low MGMT mRNA expression was strongly predictive for prolonged time to progression, treatment response, and length of survival in univariate and multivariate models (p<0.0001); the degree of MGMT mRNA expression was highly correlated with the MGMT promoter methylation status (p<0.0001); however, discordant findings were seen in 12 glioblastoma patients: Patients with methylated tumors with high MGMT mRNA expression (N = 6) did significantly worse than those with low transcriptional activity (p<0.01). Conversely, unmethylated tumors with low MGMT mRNA expression (N = 6) did better than their counterparts. A nearly identical frequency of concordant and discordant findings was obtained by analyzing the TCGA database (p<0.0001). Expression of DNMT1 and DNMT3b was strongly upregulated in tumor tissue, but not correlated with MGMT promoter methylation and MGMT mRNA expression.
Conclusions/Significance:
MGMT mRNA expression plays a direct role for mediating tumor sensitivity to alkylating agents. Discordant findings indicate methylation-independent pathways of MGMT expression regulation. DNMT1 and DNMT3b are likely to be involved in CGI methylation. However, their exact role yet has to be defined
Impact of implementing a non-restrictive antibiotic stewardship program in an emergency department: a four-year quasi-experimental prospective study
No full textAntibiotic resistance is increasing worldwide. The implementation of antibiotic stewardship programmes (ASPs) is of utmost importance to optimize antibiotic use in order to prevent resistance development without harming patients. The emergency department (ED), cornerstone between hospital and community, represents a crucial setting for addressing ASP implementation; however, evidence data on ASP in ED are poor. In this study, a 4-year, non-restrictive, multi-faceted ASP was implemented in a general ED with the aim to evaluate its impact on antibiotic use and costs. Secondly, the study focused on assessing the impact on length of hospital stay (LOS), Clostridioides difficile infection (CDI) incidence rate, and mortality in the patients' group admitted from ED to medical wards. The ASP implementation was associated with a reduction of antibiotic use and costs. A mild but sustained LOS decrease in all medical wards and a significant downward trend of CDI incidence rate were observed, while mortality did not significantly change. In conclusion, the implementation of our ED-based ASP has demonstrated to be feasible and safe and might clinically benefit the hospital admitted patients' group. Further research is needed to identify the most suitable ASP design for ED and the key outcome measures to reliably assess its effectiveness
Genexpressionsprofil ausgewählter leukozytärer miRNA von Mäusen veschiedenen Alters mit polymikrobieller Sepsis
No full textDie vorliegende Arbeit hat zum Ziel, das murine miRNA-Genexpressionsprofil in zirkulierenden Leukozyten nach Induktion einer polymikrobiellen Sepsis zu untersuchen. Erwartet wird eine signifikante Änderung des murinen miRNA-Genexpressionsprofils mit zunehmendem Alter. Damit soll die Bedeutung muriner Alterungsmodelle in der Sepsisforschung dokumentiert und diskutiert werden. Zusätzlich werden zehn sepsisrelevante miRNAs selektiert und einer qRT-PCR unterzogen. Die vorliegende randomisierte kontrollierte tierexperimentelle Studie arbeitet mit 24 Mäusen einer Interventionsgruppe und 12 Mäusen einer Kontrollgruppe. Beide Gruppen wurden in drei Altersstufen von 4, 12 und 24 Monate alten Mäusen unterteilt. Den Mäusen der Interventionsgruppe wurde eine polymikrobielle Sepsis durch die intra-abdominelle Injektion einer Faeces-Suspension nach dem Protokoll des PCI-Modells induziert. Das leukozytäre miRNA-Profil wurde mit Hilfe der Microarray Genexpressionsanalyse bestimmt. Die zehn sepsisrelevante miRNAs wurden in einer qRT-PCR untersucht. Die Auswertung der Daten des Microarray Versuchs zeigt, dass die gerade geschlechtsreifen Mäuse auf die Sepsisinduktion mit einer signifikanten miRNA-Genexpressionsänderung reagieren, während sich das miRNA-Profil der adulten und der senilen Mäuse nur in sehr begrenztem Umfang verändert. Auch in der Sham-Gruppe verändert sich physiologisch das miRNA-Genexpressionsmuster signifikant mit dem Alter. Die qRT-PCR bestätigt diese Ergebnisse. Die gerade geschlechtsreifen Mäuse reagieren auf Sepsis mit erhöhter Transkription der zehn sepsisrelevanten miRNAs. Mit zunehmendem Alter wird das Reaktionsniveau deutlich schwächer. Die Ergebnisse der vorliegenden Untersuchung belegen eindeutig, dass in der tierexperimentellen Sepsisforschung Alterungsmodelle unbedingt Beachtung finden müssen. In zukünftigen Untersuchungen sollten diesbezüglich vermehrt gealterte Versuchstiere verwendet werden
Thongs I've Seen (or Portrait of a Single-Subject Credential)
No full textThis is what happens when a 21st century teachers' college shares a neighborhood with a high school and a shopping mall. The fabric of the three become so intertwined that the teacher credential is just another brand. About the Author Helen M. Kress is an Assistant Professor of Education at D'Youville College in Buffalo, New York, USA. Her research interests include critical theories of education, youth cultures, multicultural curriculum, and qualitative research methods. She teaches philosophy and sociology of education to student teachers. Helen Kress can be contacted at: [email protected]
MicroRNAs as Clinical Biomarkers and Therapeutic Tools in Perioperative Medicine
No full textOver the past decade, evolutionarily conserved, noncoding small RNAs-so-called microRNAs (miRNAs)-have emerged as important regulators of virtually all cellular processes. miRNAs influence gene expression by binding to the 3'-untranslated region of protein-coding RNA, leading to its degradation and translational repression. In medicine, miRNAs have been revealed as novel, highly promising biomarkers and as attractive tools and targets for novel therapeutic approaches. miRNAs are currently entering the field of perioperative medicine, and they may open up new perspectives in anesthesia, critical care, and pain medicine. In this review, we provide an overview of the biology of miRNAs and their potential role in human disease. We highlight current paradigms of miRNA-mediated effects in perioperative medicine and provide a survey of miRNA biomarkers in the field known so far. Finally, we provide a perspective on miRNA-based therapeutic opportunities and perspectives. (Anesth Analg 2018;126: 670-81
Ghrelin, A Novel Peptide Hormone in the Regulation of Energy Balance and Cardiovascular Function
No full textSelection of reliable reference genes for quantitative real-time PCR in human T cells and neutrophils
No full textAbstract Background The choice of reliable reference genes is a prerequisite for valid results when analyzing gene expression with real-time quantitative PCR (qPCR). This method is frequently applied to study gene expression patterns in immune cells, yet a thorough validation of potential reference genes is still lacking for most leukocyte subtypes and most models of their in vitro stimulation. In the current study, we evaluated the expression stability of common reference genes in two widely used cell culture models-anti-CD3/CD28 activated T cells and lipopolysaccharide stimulated neutrophils-as well as in unselected untreated leukocytes. Results The mRNA expression of 17 (T cells), 7 (neutrophils) or 8 (unselected leukocytes) potential reference genes was quantified by reverse transcription qPCR, and a ranking of the preselected candidate genes according to their expression stability was calculated using the programs NormFinder, geNorm and BestKeeper. IPO8, RPL13A, TBP and SDHA were identified as suitable reference genes in T cells. TBP, ACTB and SDHA were stably expressed in neutrophils. TBP and SDHA were also the most stable genes in untreated total blood leukocytes. The critical impact of reference gene selection on the estimated target gene expression is demonstrated for IL-2 and FIH expression in T cells. Conclusions The study provides a shortlist of suitable reference genes for normalization of gene expression data in unstimulated and stimulated T cells, unstimulated and stimulated neutrophils and in unselected leukocytes.</p
Intronic miR-744 inhibits glioblastoma migration by functionally antagonizing its host gene MAP2K4
No full textreceptor gene in human granulocytes: identification, characterization, and functional impact on activation
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