121 research outputs found
A Fr\'{e}chet law and an Erd\"os-Philipp law for maximal cuspidal windings
In this paper we establish a Fr\'{e}chet law for maximal cuspidal windings of
the geodesic flow on a Riemannian surface associated with an arbitrary finitely
generated, essentially free Fuchsian group with parabolic elements. This result
extends previous work by Galambos and Dolgopyat and is obtained by applying
Extreme Value Theory. Subsequently, we show that this law gives rise to an
Erd\"os-Philipp law and to various generalised Khintchine-type results for
maximal cuspidal windings. These results strengthen previous results by
Sullivan, Stratmann and Velani for Kleinian groups, and extend earlier work by
Philipp on continued fractions, which was inspired by a conjecture of Erd\"os
Short Hypoxia Does not Affect Plasma Leptin in Healthy Men under Euglycemic Clamp Conditions
Leptin is involved in the endocrine control of energy expenditure and body weight regulation. Previous studies emphasize a relationship between hypoxic states and leptin concentrations. The aim of this study was to investigate the effects of acute hypoxia on leptin concentrations in healthy subjects. We examined 14 healthy men. Hypoxic conditions were induced by decreasing oxygen saturation to 75% for 30 minutes. Plasma leptin concentrations were determined at baseline, after 3 hours of euglycemic clamping, during hypoxia, and repeatedly the following 2.5 hours thereafter. Our results show an increase of plasma leptin concentrations in the course of 6 hours of hyperinsulinemic-euglycemic clamping which may reflect diurnal rhythmicity. Notwithstanding, there was no difference between levels of leptin in the hypoxic and the normoxic condition (P = .2). Since we did not find any significant changes in leptin responses upon hypoxia, plasma leptin levels do not seem to be affected by short hypoxic episodes of moderate degree
Incidence of brain injuries in a large cohort of very preterm and extremely preterm infants at term-equivalent age: results of a single tertiary neonatal care center over 10 years
OBJECTIVES
Cerebral magnetic resonance imaging (cMRI) at term-equivalent age (TEA) can detect brain injury (BI) associated with adverse neurological outcomes in preterm infants. This study aimed to assess BI incidences in a large, consecutive cohort of preterm infants born < 32 weeks of gestation, the comparison between very (VPT, ≥ 28 + 0 to < 32 + 0 weeks of gestation) and extremely preterm infants (EPT, < 28 + 0 weeks of gestation) and across weeks of gestation.
METHODS
We retrospectively analyzed cMRIs at TEA of VPT and EPT infants born at a large tertiary center (2009-2018). We recorded and compared the incidences of BI, severe BI, intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction (PVHI), cerebellar hemorrhage (CBH), cystic periventricular leukomalacia (cPVL), and punctate white matter lesions (PWML) between VPTs, EPTs, and across weeks of gestation.
RESULTS
We included 507 preterm infants (VPT, 335/507 (66.1%); EPT, 172/507 (33.9%); mean gestational age (GA), 28 + 2 weeks (SD 2 + 2 weeks); male, 52.1%). BIs were found in 48.3% of the preterm infants (severe BI, 12.0%) and increased with decreasing GA. IVH, PVHI, CBH, cPVL, and PWML were seen in 16.8%, 0.8%, 10.5%, 3.4%, and 18.1%, respectively. EPT vs. VPT infants suffered more frequently from BI (59.3% vs. 42.7%, p < 0.001), severe BI (18.6% vs. 8.7%, p = 0.001), IVH (31.9% vs. 9.0%, p < 0.001), and CBH (18.0% vs. 6.6%, p < 0.001).
CONCLUSION
Brain injuries are common cMRI findings among preterm infants with a higher incidence of EPT compared to VPT infants. These results may serve as reference values for clinical management and research.
CLINICAL RELEVANCE STATEMENT
Our results with regard to gestational age might provide valuable clinical insights, serving as a key reference for parental advice, structured follow-up planning, and enhancing research and management within the Neonatal Intensive Care Unit.
KEY POINTS
Brain injury is a common cMRI finding in preterm infants seen in 48.3% individuals. • Extremely preterm compared to very preterm infants have higher brain injury incidences driven by brain injuries such as intraventricular and cerebellar hemorrhage. • Reference incidence values are crucial for parental advice and structured follow-up planning
Genome-Wide Massively Parallel Sequencing of Formaldehyde Fixed-Paraffin Embedded (FFPE) Tumor Tissues for Copy-Number- and Mutation-Analysis
Cancer re-sequencing programs rely on DNA isolated from fresh snap frozen tissues, the preparation of which is combined with additional preservation efforts. Tissue samples at pathology departments are routinely stored as formalin-fixed and paraffin-embedded (FFPE) samples and their use would open up access to a variety of clinical trials. However, FFPE preparation is incompatible with many down-stream molecular biology techniques such as PCR based amplification methods and gene expression studies.
Methodology/Principal Findings
Here we investigated the sample quality requirements of FFPE tissues for massively parallel short-read sequencing approaches. We evaluated key variables of pre-fixation, fixation related and post-fixation processes that occur in routine medical service (e.g. degree of autolysis, duration of fixation and of storage). We also investigated the influence of tissue storage time on sequencing quality by using material that was up to 18 years old. Finally, we analyzed normal and tumor breast tissues using the Sequencing by Synthesis technique (Illumina Genome Analyzer, Solexa) to simultaneously localize genome-wide copy number alterations and to detect genomic variations such as substitutions and point-deletions and/or insertions in FFPE tissue samples.
Conclusions/Significance
The application of second generation sequencing techniques on small amounts of FFPE material opens up the possibility to analyze tissue samples which have been collected during routine clinical work as well as in the context of clinical trials. This is in particular important since FFPE samples are amply available from surgical tumor resections and histopathological diagnosis, and comprise tissue from precursor lesions, primary tumors, lymphogenic and/or hematogenic metastases. Large-scale studies using this tissue material will result in a better prediction of the prognosis of cancer patients and the early identification of patients which will respond to therapy
Evidence for a Relationship between VEGF and BMI Independent of Insulin Sensitivity by Glucose Clamp Procedure in a Homogenous Group Healthy Young Men
BACKGROUND: This is the first study to experimentally explore the direct relationship between circulating VEGF levels and body mass index (BMI) as well as to unravel the role of insulin sensitivity in this context under standardized glucose clamp conditions as the methodical gold-standard. In order to control for known influencing factors such as gender, medication, and arterial hypertension, we examined a highly homogeneous group of young male subjects. Moreover, to encompass also subjects beyond the normal BMI range, low weight and obese participants were additionally included and stress hormones as a main regulator of VEGF were assessed. METHODOLOGY/PRINCIPAL FINDINGS: Under euglycemic clamp conditions, VEGF was measured in 15 normal weight (BMI 20-25 kg/m(2)), 15 low weight (BMI<20 kg/m(2)), and 15 obese (BMI>30 kg/m(2)) male subjects aged 18-30 years and the insulin sensitivity index (ISI) was calculated. Since stress axis activation promotes VEGF secretion, concentrations of ACTH, cortisol, and catecholamines were monitored. Despite of comparable ACTH (P = 0.145), cortisol (P = 0.840), and norepinephrine (P = 0.065) levels, VEGF concentrations differed significantly between BMI-groups (P = 0.008) with higher concentrations in obese subjects as compared to normal weight (P = 0.061) and low weight subjects (P = 0.002). Pearson's correlation analysis revealed a positive relationship between BMI and VEGF levels (r = 0.407; P = 0.010) but no correlation of VEGF with ISI (r = 0.224; P = 0.175). CONCLUSIONS/SIGNIFICANCE: Our data demonstrate a positive correlation between concentrations of circulating VEGF levels and BMI in healthy male subjects under highly controlled conditions. This relationship which is apparently disconnected from insulin sensitivity may be part of some pathogenetic mechanisms underlying obesity and type 2 diabetes
Bildgebung des Retinoblastoms : Aktueller Stand der Technik und Ausblick in die Zukunft
Hintergrund
Das Retinoblastom ist der häufigste bösartige Augentumor im Kindesalter und in bis zu 40 % der Fälle mit einem Tumorprädispositionssyndrom assoziiert (RB1-Mutation). Die Bildgebung ist ein wichtiger Bestandteil der diagnostischen Evaluation von Kindern mit Retinoblastom zum Zeitpunkt der Diagnose und im Follow-up.
Ziel der Arbeit
Diese Übersichtsarbeit soll den aktuellen Stand der Technik und wichtige diagnostische Aspekte der radiologischen Bildgebung von Kindern mit Retinoblastom aufzeigen mit einem kurzen Ausblick in die Zukunft. Zusätzlich wird ein Überblick über die allgemeine klinische Diagnostik und die Therapiemöglichkeiten gegeben.
Material und Methoden
Basis der Arbeit ist die Recherche in verschiedenen Literaturdatenbanken sowie eigene Erfahrungen in der Bildgebung des Retinoblastoms.
Schlussfolgerung
Hochaufgelöste MRT-Bildgebung ist die Bildgebungsmodalität der Wahl bei Kindern mit Retinoblastomen zum Zeitpunkt der Diagnose (Abklärung der Diagnose/möglicher Differenzialdiagnosen, Evaluation der Tumorausdehnung okulär und intrakraniell) und im Follow-up. CT-Untersuchungen sind trotz der charakteristischen Verkalkungen zur Diagnostik nicht mehr indiziert. Da Retinoblastome bis zu 40 % mit Tumorprädispositionssyndromen assoziiert sind, sollte stets auch eine genetische Abklärung erfolgen.
=
Background
Retinoblastoma is the most common malignant eye tumor in children and is associated with tumor predisposition syndrome (RB1 mutation) in up to 40% of cases. Imaging is an important part of the diagnostic workup of children with retinoblastoma both during the initial diagnosis and follow-up.
Objectives
The goal of this review is to present the current state-of-the-art regarding imaging of children with retinoblastoma, including technical background and diagnostic clues with a brief discussion of future prospects. In addition, we summarize the general clinical diagnostic workup and therapeutic options.
Materials and methods
Review of the literature and our own experience in the imaging of retinoblastoma.
Conclusion
High-resolution magnetic resonance imaging (MRI) is the imaging modality of choice in children with retinoblastoma for diagnosis (estimation of diagnosis/differential diagnosis, evaluation of local and intracranial tumor extension) and during follow-up. Despite the characteristic calcifications, computed tomography (CT) examinations are no longer indicated in these patients. Due to the high association with tumor predisposition syndrome, genetic counselling is recommended
Anterior gradient 2 and 3 – two prototype androgen‐responsive genes transcriptionally upregulated by androgens and by oestrogens in prostate cancer cells
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96748/1/febs12118.pd
A de novo CSDE1 variant causing neurodevelopmental delay, intellectual disability, neurologic and psychiatric symptoms in a child of consanguineous parents.
Funder: National Human Genome Research Institute; Id: http://dx.doi.org/10.13039/100000051Funder: Broad Institute; Id: http://dx.doi.org/10.13039/100013114Funder: Horizon 2020; Id: http://dx.doi.org/10.13039/100010661Funder: Muscular Dystrophy Canada; Id: http://dx.doi.org/10.13039/501100000223Funder: Evelyn Trust; Id: http://dx.doi.org/10.13039/501100004282Funder: European Regional Development Fund; Id: http://dx.doi.org/10.13039/501100008530CSDE1 encodes the cytoplasmic cold shock domain-containing protein E1 (CSDE1), which is highly conserved across species and functions as an RNA-binding protein involved in translationally coupled mRNA turnover. CSDE1 displays a bidirectional role: promoting and repressing the translation of RNAs but also increasing and decreasing the abundance of RNAs. Preclinical studies highlighted an involvement of CSDE1 in different forms of cancer. Moreover, CSDE1 is highly expressed in human embryonic stem cells and plays a role in neuronal migration and differentiation. A genome-wide association study suggested CSDE1 as a potential autism-spectrum disorder risk gene. A multicenter next generation sequencing approach unraveled likely causative heterozygous variants in CSDE1 in 18 patients, identifying a new autism spectrum disorder-related syndrome consisting of autism, intellectual disability, and neurodevelopmental delay. Since then, no further patients with CSDE1 variants have been reported in the literature. Here, we report a 9.5-year-old girl from a consanguineous family of Turkish origin suffering from profound delayed speech and motor development, moderate intellectual disability, neurologic and psychiatric symptoms as well as hypoplasia of corpus callosum and mildly reduced brain volume on brain magnetic resonance imaging associated with a recurrent de novo mutation in CSDE1 (c.367C > T; p.R123*) expanding the phenotypical spectrum associated with pathogenic CSDE1 variants
High-Throughput miRNA and mRNA Sequencing of Paired Colorectal Normal, Tumor and Metastasis Tissues and Bioinformatic Modeling of miRNA-1 Therapeutic Applications
MiRNAs are discussed as diagnostic and therapeutic molecules. However,
effective miRNA drug treatments with miRNAs are, so far, hampered by the
complexity of the miRNA networks. To identify potential miRNA drugs in
colorectal cancer, we profiled miRNA and mRNA expression in matching normal,
tumor and metastasis tissues of eight patients by Illumina sequencing. We
validated six miRNAs in a large tissue screen containing 16 additional tumor
entities and identified miRNA-1, miRNA-129, miRNA-497 and miRNA-215 as
constantly de-regulated within the majority of cancers. Of these, we
investigated miRNA-1 as representative in a systems-biology simulation of
cellular cancer models implemented in PyBioS and assessed the effects of
depletion as well as overexpression in terms of miRNA-1 as a potential
treatment option. In this system, miRNA-1 treatment reverted the disease
phenotype with different effectiveness among the patients. Scoring the gene
expression changes obtained through mRNA-Seq from the same patients we show
that the combination of deep sequencing and systems biological modeling can
help to identify patient-specific responses to miRNA treatments. We present
this data as guideline for future pre-clinical assessments of new and
personalized therapeutic options
- …