Establishing a diagnosis in patients suspected of having a myelodysplastic syndrome (MDS) can be challenging and could be informed by the identification of somatic mutations. We performed a ...prospective study to examine the frequency and types of mutations encountered in 144 patients with unexplained cytopenias. Based on bone marrow findings, 17% were diagnosed with MDS, 15% with idiopathic cytopenias of undetermined significance (ICUS) and some evidence of dysplasia, and 69% with ICUS and no dysplasia. Bone marrow DNA was sequenced for mutations in 22 frequently mutated myeloid malignancy genes. Somatic mutations were identified in 71% of MDS patients, 62% of patients with ICUS and some dysplasia, and 20% of ICUS patients and no dysplasia. In total, 35% of ICUS patients carried a somatic mutation or chromosomal abnormality indicative of clonal hematopoiesis. We validated these results in a cohort of 91 lower-risk MDS and 249 ICUS cases identified over a 6-month interval. Mutations were found in 79% of those with MDS, in 45% of those with ICUS with dysplasia, and in 17% of those with ICUS without dysplasia. The spectrum of mutated genes was similar with the exception of SF3B1 which was rarely mutated in patients without dysplasia. Variant allele fractions were comparable between clonal ICUS (CCUS) and MDS as were mean age and blood counts. We demonstrate that CCUS is a more frequent diagnosis than MDS in cytopenic patients. Clinical and mutational features are similar in these groups and may have diagnostic utility once outcomes in CCUS patients are better understood.
•Over 30% of patients with unexplained cytopenias who do not meet diagnostic criteria for MDS carry MDS-associated somatic mutations.•Clonal cytopenias of undetermined significance are more common than MDS and show comparable variant allele frequencies and blood counts.
Objective
Although most temporal lobe epilepsy (TLE) patients show marked hippocampal sclerosis (HS) upon pathological examination, 40% present with no significant cell loss but gliotic changes only. ...To evaluate effects of hippocampal pathology on brain structure and functional networks, we aimed at dissociating multimodal magnetic resonance imaging (MRI) characteristics in patients with HS (TLE‐HS) and those with gliosis only (TLE‐G).
Methods
In 20 TLE‐HS, 19 TLE‐G, and 25 healthy controls, we carried out a novel MRI‐based hippocampal subfield surface analysis that integrated volume, T2 signal intensity, and diffusion markers with seed‐based hippocampal functional connectivity.
Results
Compared to controls, TLE‐HS presented with marked ipsilateral atrophy, T2 hyperintensity, and mean diffusivity increases across all subfields, whereas TLE‐G presented with dentate gyrus hypertrophy, focal increases in T2 intensity and mean diffusivity. Multivariate assessment confirmed a more marked ipsilateral load of anomalies across all subfields in TLE‐HS, whereas anomalies in TLE‐G were restricted to the subiculum. A between‐cohort dissociation was independently suggested by resting‐state functional connectivity analysis, revealing marked hippocampal decoupling from anterior and posterior default mode hubs in TLE‐HS, whereas TLE‐G did not differ from controls. Back‐projection connectivity analysis from cortical targets revealed consistently decreased network embedding across all subfields in TLE‐HS, while changes in TLE‐G were limited to the subiculum. Hippocampal disconnectivity strongly correlated to T2 hyperintensity and marginally to atrophy.
Interpretation
Multimodal MRI reveals diverging structural and functional connectivity profiles across the TLE spectrum. Pathology‐specific modulations of large‐scale functional brain networks lend novel evidence for a close interplay of structural and functional disruptions in focal epilepsy. Ann Neurol 2016;80:142–153
Abstract Stereo-electroencephalography (SEEG) is the gold standard to delineate surgical targets in focal drug-resistant epilepsy. SEEG uses electrodes placed directly into the brain to identify the ...seizure-onset zone (SOZ). However, its major constraint is limited brain coverage, potentially leading to misidentification of the ‘true’ SOZ. Here, we propose a framework to assess adequate SEEG sampling by coupling epileptic biomarkers with their spatial distribution and measuring the system’s response to a perturbation of this coupling. We demonstrate that the system’s response is strongest in well-sampled patients when virtually removing the measured SOZ. We then introduce the spatial perturbation map, a tool that enables qualitative assessment of the implantation coverage. Probability modelling reveals a higher likelihood of well-implanted SOZs in seizure-free patients or non-seizure free patients with incomplete SOZ resections, compared to non-seizure-free patients with complete resections. This highlights the framework’s value in sparing patients from unsuccessful surgeries resulting from poor SEEG coverage.
Adult T-cell leukemia lymphoma (ATLL) is a rare T cell neoplasm that is endemic in Japanese, Caribbean, and Latin American populations. Most North American ATLL patients are of Caribbean descent and ...are characterized by high rates of chemo-refractory disease and worse prognosis compared with Japanese ATLL. To determine genomic differences between these 2 cohorts, we performed targeted exon sequencing on 30 North American ATLL patients and compared the results with the Japanese ATLL cases. Although the frequency of TP53 mutations was comparable, the mutation frequency in epigenetic and histone modifying genes (57%) was significantly higher, whereas the mutation frequency in JAK/STAT and T-cell receptor/NF-κB pathway genes was significantly lower. The most common type of epigenetic mutation is that affecting EP300 (20%). As a category, epigenetic mutations were associated with adverse prognosis. Dissimilarities with the Japanese cases were also revealed by RNA sequencing analysis of 9 primary patient samples. ATLL samples with a mutated EP300 gene have decreased total and acetyl p53 protein and a transcriptional signature reminiscent of p53-mutated cancers. Most importantly, decitabine has highly selective single-agent activity in the EP300-mutated ATLL samples, suggesting that decitabine treatment induces a synthetic lethal phenotype in EP300-mutated ATLL cells. In conclusion, we demonstrate that North American ATLL has a distinct genomic landscape that is characterized by frequent epigenetic mutations that are targetable preclinically with DNA methyltransferase inhibitors.
•North American ATLL has a distinct genomic landscape with a high frequency of prognostic epigenetic mutations, including EP300 mutations.•ATLL samples with mutated EP300 have compromised p53 function and are selectively sensitive to decitabine treatment.
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Few studies have examined Chinese patients with chronic hepatitis B who exhibit hepatitis B surface antigen (HBsAg) seroclearance. We comprehensively studied the biochemical, virological, ...histological, and clinical aspects of 92 patients with HBsAg seroclearance (median follow‐up, 126 months). Ninety‐two HBsAg‐positive controls matched for age, sex, and duration of follow‐up were also recruited. Liver biochemistry, serum hepatitis B virus (HBV) DNA levels, and development of clinical complications were monitored. Intrahepatic total and covalently closed circular (ccc) HBV DNA were measured quantitatively in 16 patients. HBV genotype was determined in 30 patients. The mean age at HBsAg seroclearance was 48.8 (+ 13.81) years. There was a significant improvement in serum alanine aminotransferase levels after HBsAg seroclearance (p<0.0001). Patients with genotype B had a higher chance of HBsAg seroclearance than those with genotype C (P = .014). Ninety‐eight percent of patients had undetectable serum HBV DNA. Thirty‐seven percent of patients had low titer of intrahepatic HBV DNA, mainly in the form of cccDNA (71%‐100%). All 14 patients with liver biopsies had near normal histology. There was no difference in the risk of development of hepatocellular carcinoma (HCC) between patients with and without HBsAg seroclearance. However, the mean age of HBsAg seroclearance was significantly older in patients with HCC than in patients without HCC (P = .016). In conclusion, patients with HBsAg seroclearance had favorable biochemical, virological, and histological parameters. Intrahepatic HBV DNA level was low and predominantly in the form of cccDNA. However, HCC could still develop, particularly in patients with cirrhosis who had HBsAg seroclearance at an older age. (HEPATOLOGY 2004;39:1694–1701.)
Tumor necrosis factor (TNF) and interleukin (IL)-17A are pleiotropic cytokines implicated in the pathogenesis of several autoimmune diseases including rheumatoid arthritis (RA) and psoriatic ...arthritis (PsA). JNJ-61178104 is a novel human anti-TNF and anti-IL-17A monovalent, bispecific antibody that binds to both human TNF and human IL-17A with high affinities and blocks the binding of TNF and IL-17A to their receptors
. JNJ-61178104 also potently neutralizes TNF and IL-17A-mediated downstream effects in multiple cell-based assays.
, treatment with JNJ-61178104 resulted in dose-dependent inhibition of cellular influx in a human IL-17A/TNF-induced murine lung neutrophilia model and the inhibitory effects of JNJ-61178104 were more potent than the treatment with bivalent parental anti-TNF or anti-IL-17A antibodies. JNJ-61178104 was shown to engage its targets, TNF and IL-17A, in systemic circulation measured as drug/target complex formation in normal cynomolgus monkeys (cyno). Surprisingly, quantitative target engagement assessment suggested lower apparent
target-binding affinities for JNJ-61178104 compared to its bivalent parental antibodies, despite their similar
target-binding affinities. The target engagement profiles of JNJ-61178104 in humans were in general agreement with the predicted profiles based on cyno data, suggesting similar differences in the apparent
target-binding affinities. These findings show that
target engagement of monovalent bispecific antibody does not necessarily recapitulate that of the molar-equivalent dose of its bivalent parental antibody. Our results also offer valuable insights into the understanding of the pharmacokinetics/pharmacodynamics and target engagement of other bispecific biologics against dimeric and/or trimeric soluble targets
.
Flap endonucleases (FENs) isolated from archaea are shown to recognize and cleave a structure formed when two overlapping oligonucleotides hybridize to a target DNA strand. The downstream ...oligonucleotide probe is cleaved, and the precise site of cleavage is dependent on the amount of overlap with the upstream oligonucleotide. We have demonstrated that use of thermostable archaeal FENs allows the reaction to be performed at temperatures that promote probe turnover without the need for temperature cycling. The resulting amplification of the cleavage signal enables the detection of specific DNA targets at sub-attomole levels within complex mixtures. Moreover, we provide evidence that this cleavage is sufficiently specific to enable discrimination of single-base differences and can differentiate homozygotes from heterozygotes in single-copy genes in genomic DNA.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Living in rural Maine, Jeffrey Hall’s own rhythm has been thrown upside down after he received a very unexpected call one morning on the award of this year’s Nobel Prize in Physiology or Medicine. ...Together with Michael Rosbash and Mike Young, they were recognized “for their discoveries of molecular mechanisms controlling the circadian rhythm.” Cell editor Marta Koch caught up with Jeff on a calm Sunday morning, when electricity at his house had just returned after recent storms. Annotated excerpts from their chat about behavior, misbehavior, and the challenges and joys of working with fruit flies, are presented below.
Living in rural Maine, Jeffrey Hall’s own rhythm has been thrown upside down after he received a very unexpected call one morning on the award of this year’s Nobel Prize in Physiology or Medicine. Together with Michael Rosbash and Mike Young, they were recognized “for their discoveries of molecular mechanisms controlling the circadian rhythm.” Cell editor Marta Koch caught up with Jeff on a calm Sunday morning, when electricity at his house had just returned after recent storms. Annotated excerpts from their chat about behavior, misbehavior, and the challenges and joys of working with fruit flies, are presented below.
The invasive signal amplification reaction has been previously developed for quantitative detection of nucleic acids and discrimination of single-nucleotide polymorphisms. Here we describe a method ...that couples two invasive reactions into a serial isothermal homogeneous assay using fluorescence resonance energy transfer detection. The serial version of the assay generates more than 107reporter molecules for each molecule of target DNA in a 4-h reaction; this sensitivity, coupled with the exquisite specificity of the reaction, is sufficient for direct detection of less than 1,000 target molecules with no prior target amplification. Here we present a kinetic analysis of the parameters affecting signal and background generation in the serial invasive signal amplification reaction and describe a simple kinetic model of the assay. We demonstrate the ability of the assay to detect as few as 600 copies of the methylene tetrahydrofolate reductase gene in samples of human genomic DNA. We also demonstrate the ability of the assay to discriminate single base differences in this gene by using 20 ng of human genomic DNA.
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