549 research outputs found
Acute Myeloid Leukemia
Acute myeloid leukemia (AML) is the most common type of leukemia. The Cancer Genome Atlas Research Network has demonstrated the increasing genomic complexity of acute myeloid leukemia (AML). In addition, the network has facilitated our understanding of the molecular events leading to this deadly form of malignancy for which the prognosis has not improved over past decades. AML is a highly heterogeneous disease, and cytogenetics and molecular analysis of the various chromosome aberrations including deletions, duplications, aneuploidy, balanced reciprocal translocations and fusion of transcription factor genes and tyrosine kinases has led to better understanding and identification of subgroups of AML with different prognoses. Furthermore, molecular classification based on mRNA expression profiling has facilitated identification of novel subclasses and defined high-, poor-risk AML based on specific molecular signatures. However, despite increased understanding of AML genetics, the outcome for AML patients whose number is likely to rise as the population ages, has not changed significantly. Until it does, further investigation of the genomic complexity of the disease and advances in drug development are needed. In this review, leading AML clinicians and research investigators provide an up-to-date understanding of the molecular biology of the disease addressing advances in diagnosis, classification, prognostication and therapeutic strategies that may have significant promise and impact on overall patient survival
Clinical exome performance for reporting secondary genetic findings.
BACKGROUND
:
Reporting clinically actionable incidental
genetic findings in the course of clinical exome testing is
recommended by the American College of Medical Genet-
ics and Genomics (ACMG). However, the performance of
clinical exome methods for reporting small subsets of genes
has not been previously reported.
METHODS
:
In this study, 57 exome data sets performed as
clinical (n
!
12) or research (n
!
45) tests were retrospec-
tively analyzed. Exome sequencing data was examined for
adequacy in the detection of potentially pathogenic variant
locations in the 56 genes described in the ACMG incidental
findings recommendation. All exons of the 56 genes were
examined for adequacy of sequencing coverage. In addition,
nucleotide positions annotated in HGMD (Human Gene
Mutation Database) were examined.
RESULTS
:
The 56 ACMG genes have 18336 nucleotide
variants annotated in HGMD. None of the 57 exome
data sets possessed a HGMD variant. The clinical exome
test had inadequate coverage for
"
50% of HGMD vari-
ant locations in 7 genes. Six exons from 6 different genes
had consistent failure across all 3 test methods; these
exons had high GC content (76%–84%).
CONCLUSIONS
:
The use of clinical exome sequencing
for the interpretation and reporting of subsets of genes
requires recognition of the substantial possibility of
inadequate depth and breadth of sequencing coverage
at clinically relevant locations. Inadequate depth of
coverage may contribute to false-negative clinical ex-
ome results
Analytical Ancestry: "Firsts" in Fluorescent Labeling of Nucleosides, Nucleotides, and Nucleic Acids
Production of laccase by Botrytis cinerea and fermentation studies with strain F226
After induction, seven strains ofBotrytis cinerea released into the culture broth considerable amounts of laccase in a brief production time. The set-up of a suitable production process was studied with a selected strain in a 10-L fermenter. The optimum fermentation conditions were a 3% inoculum with a high degree of sporulation, a simple medium containing 20 g L−1 of glucose and 2 g L−1 of yeast extract at pH 3.5, 2 g L−1 gallic acid as inducer, added after 2 days of growth, an agitation speed of 300 rpm, an aeration rate of 1.2 vvm and a temperature of 24°C. By optimizing the culture conditions, the enzyme activity reached 28 U ml−1 in 5 days with a specific activity of 560 U mg−1 protein. The best procedure to obtain a suitable crude enzyme preparation was concentration of the supernatant medium to 10% of the initial volume by ultrafiltration, followed by a fractional precipitation with ethanol. The optimum pH and temperature for laccase activity were 5.5 and 40°C, respectively, with syringaldazine as the substrate
In vivo E2F reporting reveals efficacious schedules of MEK1/2–CDK4/6 targeting and mTOR–s6 resistance mechanisms
Targeting cyclin-dependent kinases 4/6 (CDK4/6) represents a therapeutic option in combination with BRAF inhibitor and/or MEK inhibitor (MEKi) in melanoma; however, continuous dosing elicits toxicities in patients. Using quantitative and temporal in vivo reporting, we show that continuous MEKi with intermittent CDK4/6 inhibitor (CDK4/6i) led to more complete tumor responses versus other combination schedules. Nevertheless, some tumors acquired resistance that was associated with enhanced phosphorylation of ribosomal S6 protein. These data were supported by phospho-S6 staining of melanoma biopsies from patients treated with CDK4/6i plus targeted inhibitors. Enhanced phospho-S6 in resistant tumors provided a therapeutic window for the mTORC1/2 inhibitor AZD2014. Mechanistically, upregulation or mutation of NRAS was associated with resistance in in vivo models and patient samples, respectively, and mutant NRAS was sufficient to enhance resistance. This study utilizes an in vivo reporter model to optimize schedules and supports targeting mTORC1/2 to overcome MEKi plus CDK4/6i resistance. SIGnIFICAnCE: Mutant BRAF and NRAS melanomas acquire resistance to combined MEK and CDK4/6 inhibition via upregulation of mTOR pathway signaling. This resistance mechanism provides the preclinical basis to utilize mTORC1/2 inhibitors to improve MEKi plus CDK4/6i drug regimens
evaluation of ovine milk clotting aptitude
A comparative study of the lactodynamographic parameters was carried out on ovine milk. Besides evaluating the repeatability and reproducibility of the analytical method, the influence of some variables such as the genetic type (three breeds), the kind of milk (whole or skimmed), and its concentration after reconstitution (12g or 20g /100 ml) was evaluated. The working plan involved 6 laboratories for the final statistic analyses, by the use of freeze-dried milk samples (adequately reconstituted on the basis of established methods) from Sardinia, Comisana, and Massese ewes. All the considered variability factors showed a highly significant effect (P<0.001) on the lactodynamographic parameters considered. In particular, Massese ewe milk showed the shortest curd speed (k20) and the best coagulum strength (a30 and a45), although clotting time (CT) was the highest one. The same trend was registered for skimmed milk and for the most concentrated one (20g). Repeatability values within laboratories were 96% and 97% for CT and k20, lowering for a30 e a45, (respectively 87% and 85%). Much lower coefficients were found for the among laboratories reproducibility, ranging from a maximum of 58% for CT to a minimum of 18% for k20. The wide variability observed indicates that lactodynamographic parameters are comparable only within the same lab. Further investigation is needed to compare different labs in order to obtain more homogeneous results
Kinase-independent role of cyclin D1 in chromosomal instability and mammary tumorigenesis
Cyclin D1 is an important molecular driver of human breast cancer but better understanding of its oncogenic mechanisms is needed, especially to enhance efforts in targeted therapeutics. Currently, pharmaceutical initiatives to inhibit cyclin D1 are focused on the catalytic component since the transforming capacity is thought to reside in the cyclin D1/CDK activity. We initiated the following study to directly test the oncogenic potential of catalytically inactive cyclin D1 in an in vivo mouse model that is relevant to breast cancer. Herein, transduction of cyclin D1(-/-) mouse embryonic fibroblasts (MEFs) with the kinase dead KE mutant of cyclin D1 led to aneuploidy, abnormalities in mitotic spindle formation, autosome amplification, and chromosomal instability (CIN) by gene expression profiling. Acute transgenic expression of either cyclin D1(WT) or cyclin D1(KE) in the mammary gland was sufficient to induce a high CIN score within 7 days. Sustained expression of cyclin D1(KE) induced mammary adenocarcinoma with similar kinetics to that of the wild-type cyclin D1. ChIP-Seq studies demonstrated recruitment of cyclin D1(WT) and cyclin D1(KE) to the genes governing CIN. We conclude that the CDK-activating function of cyclin D1 is not necessary to induce either chromosomal instability or mammary tumorigenesis
Compliance of clinical microbiology laboratories with recommendations for the diagnosis of bloodstream infections
In 2014, the Italian Working Group for Infections in Critically Ill Patient of the Italian
Association of Clinical Microbiologists updated the recommendations for the diagnostic workflow for bloodstream infections (BSI). Two years after publication, a
nationwide survey was conducted to assess the compliance with the updated recommendations by clinical microbiology laboratories. A total of 168 microbiologists
from 168 laboratories, serving 204 acute care hospitals and postacute care facilities,
were interviewed during the period January\u2013October 2016 using a questionnaire
consisting of nineteen questions which assessed the level of adherence to various
recommendations. The most critical issues were as follows: (a) The number of sets
of blood cultures (BC) per 1,000 hospitalization days was acceptable in only 11% of
laboratories; (b) the minority of laboratories (42%) was able to monitor whether BCs
were over or under-inoculated; (c) among the laboratories monitoring BC contamination (80%), the rate of contaminated samples was acceptable in only 12% of cases;(d)
the Gram-staining results were reported within 1 hr since BC positivity in less than
50% of laboratories. By contrast, most laboratories received vials within 2\u20134 hr from
withdrawal (65%) and incubated vials as soon as they were received in the laboratory
(95%). The study revealed that compliance with the recommendations is still partial.
Further surveys will be needed to monitor the situation in the future
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