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On page 442 showing 8821 ~ 8840 papers out of 2,794,544 papers

Tests of the chromatographic theory of olfaction with highly soluble odors: a combined electro-olfactogram and computational fluid dynamics study in the mouse.

  • David M Coppola‎ et al.
  • Biology open‎
  • 2019‎

The idea that the vertebrate nasal cavity operates like a gas chromatograph to separate and discriminate odors, referred to herein as the 'chromatographic theory' (CT), has a long and interesting history. Though the last decade has seen renewed interest in the notion, its validity remains in question. Here we examine a necessary condition of the theory: a correlation between nasal odor deposition patterns based on mucus solubility and the distribution of olfactory sensory neuron odotypes. Our recent work in the mouse failed to find such a relationship even across large sorption gradients within the olfactory epithelium (OE). However, these studies did not test extremely soluble odorants or low odor concentrations, factors that could explain our inability to find supporting evidence for the CT. The current study combined computational fluid dynamics (CFD) simulations of odor sorption patterns and electro-olfactogram (EOG) measurements of olfactory sensory neuron responses. The odorants tested were at the extremes of mucus solubility and at a range of concentrations. Results showed no relationship between local odor sorption patterns and EOG response maps. Together, results again failed to support a necessary condition of the CT casting further doubt on the viability of this classical odor coding mechanism.


Quantification of minimal disseminated disease by quantitative polymerase chain reaction and digital polymerase chain reaction for NPM-ALK as a prognostic factor in children with anaplastic large cell lymphoma.

  • Christine Damm-Welk‎ et al.
  • Haematologica‎
  • 2020‎

Detection of minimal disseminated disease is a validated prognostic factor in ALK-positive anaplastic large cell lymphoma. We previously reported that quantification of minimal disease by quantitative real-time polymerase chain reaction (RQ-PCR) in bone marrow applying a cut-off of 10 copies NPM-ALK/104 copies of ABL1 identifies very high-risk patients. In the present study, we aimed to confirm the prognostic value of quantitative minimal disseminated disease evaluation and to validate digital polymerase chain reaction (dPCR) as an alternative method. Among 91 patients whose bone marrow was analyzed by RQ-PCR, more than 10 normalized copy-numbers correlated with stage III/IV disease, mediastinal and visceral organ involvement and low anti-ALK antibody titers. The cumulative incidence of relapses of 18 patients with more than 10 normalized copy-numbers of NPM-ALK was 61±12% compared to 21±5% for the remaining 73 patients (P=0.0002). Results in blood correlated with those in bone marrow (r=0.74) in 70 patients for whom both materials could be tested. Transcripts were quantified by RQ-PCR and dPCR in 75 bone marrow and 57 blood samples. Copy number estimates using dPCR and RQ-PCR correlated in 132 samples (r=0.85). Applying a cut-off of 30 copies NPM-ALK/104 copies ABL1 for quantification by dPCR, almost identical groups of patients were separated as those separated by RQ-PCR. In summary, the prognostic impact of quantification of minimal disseminated disease in bone marrow could be confirmed for patients with anaplastic large cell lymphoma. Blood can substitute for bone marrow. Quantification of minimal disease by dPCR provides a promising tool to facilitate harmonization of minimal disease measurement between laboratories and for clinical studies.


EVI1 triggers metabolic reprogramming associated with leukemogenesis and increases sensitivity to L-asparaginase.

  • Yusuke Saito‎ et al.
  • Haematologica‎
  • 2020‎

Metabolic reprogramming of leukemia cells is important for survival, proliferation, and drug resistance under conditions of metabolic stress in the bone marrow. Deregulation of cellular metabolism, leading to development of leukemia, occurs through abnormally high expression of transcription factors such as MYC and Ecotropic Virus Integration site 1 protein homolog (EVI1). Overexpression of EVI1 in adults and children with mixed lineage leukemia-rearrangement acute myeloid leukemia (MLL-r AML) has a very poor prognosis. To identify a metabolic inhibitor for EVI1-induced metabolic reprogramming in MLL-r AML, we used an XFp extracellular flux analyzer to examine metabolic changes during leukemia development in mouse models of AML expressing MLL-AF9 and Evi1 (Evi1/MF9). Oxidative phosphorylation (OXPHOS) in Evi1/MF9 AML cells accelerated prior to activation of glycolysis, with a higher dependency on glutamine as an energy source. Furthermore, EVI1 played a role in glycolysis as well as driving production of metabolites in the tricarboxylic acid cycle. L-asparaginase (L-asp) exacerbated growth inhibition induced by glutamine starvation and suppressed OXPHOS and proliferation of Evi1/MF9 both in vitro and in vivo; high sensitivity to L-asp was caused by low expression of asparagine synthetase (ASNS) and L-asp-induced suppression of glutamine metabolism. In addition, samples from patients with EVI1+MF9 showed low ASNS expression, suggesting that it is a sensitive marker of L-asp treatment. Clarification of metabolic reprogramming in EVI1+ leukemia cells may aid development of treatments for EVI1+MF9 refractory leukemia.


Vac8 spatially confines autophagosome formation at the vacuole in S. cerevisiae.

  • David M Hollenstein‎ et al.
  • Journal of cell science‎
  • 2019‎

Autophagy is initiated by the formation of a phagophore assembly site (PAS), the precursor of autophagosomes. In mammals, autophagosome formation sites form throughout the cytosol in specialized subdomains of the endoplasmic reticulum (ER). In yeast, the PAS is also generated close to the ER, but always in the vicinity of the vacuole. How the PAS is anchored to the vacuole and the functional significance of this localization are unknown. Here, we investigated the role of the PAS-vacuole connection for bulk autophagy in the yeast Saccharomyces cerevisiae We show that Vac8 constitutes a vacuolar tether that stably anchors the PAS to the vacuole throughout autophagosome biogenesis via the PAS component Atg13. S. cerevisiae lacking Vac8 show inefficient autophagosome-vacuole fusion, and form fewer and smaller autophagosomes that often localize away from the vacuole. Thus, the stable PAS-vacuole connection established by Vac8 creates a confined space for autophagosome biogenesis between the ER and the vacuole, and allows spatial coordination of autophagosome formation and autophagosome-vacuole fusion. These findings reveal that the spatial regulation of autophagosome formation at the vacuole is required for efficient bulk autophagy.


Dynamic oxygen adsorption on single-atomic Ruthenium catalyst with high performance for acidic oxygen evolution reaction.

  • Linlin Cao‎ et al.
  • Nature communications‎
  • 2019‎

Achieving active and stable oxygen evolution reaction (OER) in acid media based on single-atom catalysts is highly promising for cost-effective and sustainable energy supply in proton electrolyte membrane electrolyzers. Here, we report an atomically dispersed Ru1-N4 site anchored on nitrogen-carbon support (Ru-N-C) as an efficient and durable electrocatalyst for acidic OER. The single-atom Ru-N-C catalyst delivers an exceptionally intrinsic activity, reaching a mass activity as high as 3571 A gmetal-1 and turnover frequency of 3348 O2 h-1 with a low overpotential of 267 mV at a current density of 10 mA cm-2. The catalyst shows no evident deactivation or decomposition after 30-hour operation in acidic environment. Operando synchrotron radiation X-ray absorption spectroscopy and infrared spectroscopy identify the dynamic adsorption of single oxygen atom on Ru site under working potentials, and theoretical calculations demonstrate that the O-Ru1-N4 site is responsible for the high OER activity and stability.


NSD2 overexpression drives clustered chromatin and transcriptional changes in a subset of insulated domains.

  • Priscillia Lhoumaud‎ et al.
  • Nature communications‎
  • 2019‎

CTCF and cohesin play a key role in organizing chromatin into topologically associating domain (TAD) structures. Disruption of a single CTCF binding site is sufficient to change chromosomal interactions leading to alterations in chromatin modifications and gene regulation. However, the extent to which alterations in chromatin modifications can disrupt 3D chromosome organization leading to transcriptional changes is unknown. In multiple myeloma, a 4;14 translocation induces overexpression of the histone methyltransferase, NSD2, resulting in expansion of H3K36me2 and shrinkage of antagonistic H3K27me3 domains. Using isogenic cell lines producing high and low levels of NSD2, here we find oncogene activation is linked to alterations in H3K27ac and CTCF within H3K36me2 enriched chromatin. A logistic regression model reveals that differentially expressed genes are significantly enriched within the same insulated domain as altered H3K27ac and CTCF peaks. These results identify a bidirectional relationship between 2D chromatin and 3D genome organization in gene regulation.


Genome-wide microhomologies enable precise template-free editing of biologically relevant deletion mutations.

  • Janin Grajcarek‎ et al.
  • Nature communications‎
  • 2019‎

The functional effect of a gene edit by designer nucleases depends on the DNA repair outcome at the targeted locus. While non-homologous end joining (NHEJ) repair results in various mutations, microhomology-mediated end joining (MMEJ) creates precise deletions based on the alignment of flanking microhomologies (µHs). Recently, the sequence context surrounding nuclease-induced double strand breaks (DSBs) has been shown to predict repair outcomes, for which µH plays an important role. Here, we survey naturally occurring human deletion variants and identify that 11 million or 57% are flanked by µHs, covering 88% of protein-coding genes. These biologically relevant mutations are candidates for precise creation in a template-free manner by MMEJ repair. Using CRISPR-Cas9 in human induced pluripotent stem cells (hiPSCs), we efficiently create pathogenic deletion mutations for demonstrable disease models with both gain- and loss-of-function phenotypes. We anticipate this dataset and gene editing strategy to enable functional genetic studies and drug screening.


ROS-mediated inactivation of the PI3K/AKT pathway is involved in the antigastric cancer effects of thioredoxin reductase-1 inhibitor chaetocin.

  • Chuangyu Wen‎ et al.
  • Cell death & disease‎
  • 2019‎

Novel drugs are urgently needed for gastric cancer (GC) treatment. The thioredoxin-thioredoxin reductase (TRX-TRXR) system has been found to play a critical role in GC tumorigenesis and progression. Thus, agents that target the TRX-TRXR system may be highly efficacious as GC treatments. In this study, we showed that chaetocin, a natural product isolated from the Chaetomium species of fungi, inhibited proliferation, induced G2/M phase arrest and caspase-dependent apoptosis in both in vitro and in vivo models (cell xenografts and patient-derived xenografts) of GC. Chaetocin inactivated TRXR-1, resulting in the accumulation of reactive oxygen species (ROS) in GC cells; overexpression of TRX-1 as well as cotreatment of GC cells with the ROS scavenger N-acetyl-L-cysteine attenuated chaetocin-induced apoptosis; chaetocin-induced apoptosis was significantly increased when GC cells were cotreated with auranofin. Moreover, chaetocin was shown to inactivate the PI3K/AKT pathway by inducing ROS generation; AKT-1 overexpression also attenuated chaetocin-induced apoptosis. Taken together, these results reveal that chaetocin induces the excessive accumulation of ROS via inhibition of TRXR-1. This is followed by PI3K/AKT pathway inactivation, which ultimately inhibits proliferation and induces caspase-dependent apoptosis in GC cells. Chaetocin therefore may be a potential agent for GC treatment.


ACTL6A regulates follicle-stimulating hormone-driven glycolysis in ovarian cancer cells via PGK1.

  • Jiawen Zhang‎ et al.
  • Cell death & disease‎
  • 2019‎

Enhanced glycolysis has been identified as a hallmark of cancer. As a novel oncogene, ACTL6A is aberrantly amplified in several types of human cancers and has been shown to regulate tumor growth and progression. However, the roles of ACTL6A in the development of ovarian cancer and the regulation of cancer glucose metabolism are mostly unknown. Here we show that ACTL6A is overexpressed in ovarian cancers compared with adjacent non-tumor tissues, and that ACTL6A overexpression correlates with poor prognosis. Silencing of ACTL6A in vitro inhibits proliferation, clonal growth, and migration, and decreases glucose utilization, lactate production, and pyruvate levels of ovarian cancer cells. We found a positive correlation between ACTL6A and PGK1 expression in ovarian cancer tissues. Enforced ACTL6A expression increased PGK1 expression, whereas knockdown of ACTL6A had the opposite effect. Altered ACTL6A expression inhibits the tumorigenicity of ovarian cancer cells in vivo by downregulating PGK1. In addition, the expression of ACTL6A is regulated by follicle-stimulating hormone (FSH) stimulation via PI3K/AKT pathway. Importantly, ACTL6A regulates FSH-enhanced glycolysis in ovarian cancer. Taken together, our findings highlight the critical role of ACTL6A in ovarian cancer development and identify its contribution to glucose metabolism of cancer cells.


Climate-induced phenology shifts linked to range expansions in species with multiple reproductive cycles per year.

  • Callum J Macgregor‎ et al.
  • Nature communications‎
  • 2019‎

Advances in phenology (the annual timing of species' life-cycles) in response to climate change are generally viewed as bioindicators of climate change, but have not been considered as predictors of range expansions. Here, we show that phenology advances combine with the number of reproductive cycles per year (voltinism) to shape abundance and distribution trends in 130 species of British Lepidoptera, in response to ~0.5 °C spring-temperature warming between 1995 and 2014. Early adult emergence in warm years resulted in increased within- and between-year population growth for species with multiple reproductive cycles per year (n = 39 multivoltine species). By contrast, early emergence had neutral or negative consequences for species with a single annual reproductive cycle (n = 91 univoltine species), depending on habitat specialisation. We conclude that phenology advances facilitate polewards range expansions in species exhibiting plasticity for both phenology and voltinism, but may inhibit expansion by less flexible species.


Sex determination using circulating cell-free fetal DNA in small volume of maternal plasma in elephants.

  • Boglárka Vincze‎ et al.
  • Scientific reports‎
  • 2019‎

The genetic sexing of animals having long gestation periods offers significant benefits in regard to breeding management among their populations living in captivity. In our study, a new increased-sensitivity PCR method for fetal sexing was developed and tested successfully on elephants, from only a small volume of maternal plasma. Suitable sensitivity was obtained by using short, reduced amplicon lengths with fluorescent labelling for capillary electrophoresis detection. The fundamental principle for this technique was based on the detection of two Y-specific markers (AmelY and SRY), the presence of which indicates the mother is carrying a male fetus and the absence of these markers designates a female fetus. As a reaction control, the X-chromosomal marker (PlpX) was used. To the best of our knowledge, this is the first report on this topic, confirming the presence of fetal cell-free DNA from the plasma of a pregnant captive elephant, and demonstrating a new opportunity for non-invasive assessment in fetal sex determination.


Scrapie susceptibility-associated indel polymorphism of shadow of prion protein gene (SPRN) in Korean native black goats.

  • Yong-Chan Kim‎ et al.
  • Scientific reports‎
  • 2019‎

Prion diseases in sheep and goats are called scrapie and belong to a group of transmissible spongiform encephalopathies (TSEs) caused by the abnormal misfolding of the prion protein encoded by the prion protein gene (PRNP). The shadow of the prion protein gene (SPRN) is the only prion gene family member that shows a protein expression profile similar to that of the PRNP gene in the central nervous system. In addition, genetic susceptibility of the SPRN gene has been reported in variant Creutzfeldt-Jakob disease (CJD), bovine spongiform encephalopathy (BSE) and scrapie. However, genetic studies of the SPRN gene have not been carried out in Korean native black goats. Here, we investigated the genotype and allele frequencies of SPRN polymorphisms in 213 Korean native black goats and compared these polymorphisms with those previously reported for scrapie-affected animals. We found a total of 6 polymorphisms including 1 nonsynonymous single nucleotide polymorphism (SNP) and 1 synonymous SNP in the open reading frame (ORF) region and 3 SNPs and 1 indel polymorphism (c.495_496insCTCCC) in the 3' untranslated region (UTR) by direct DNA sequencing. A significant difference in the allele frequency of the c.495_496insCTCCC indel polymorphism was found between the Italian scrapie-affected goats and the Korean native black goats (P < 0.001). Furthermore, there was a significant difference in the allele frequencies of the c.495_496insCTCCC indel polymorphism between Italian healthy goats and Korean native black goats (P < 0.001). To evaluate the biological impact of the novel nonsynonymous SNP c.416G > A (Arg139Gln), we carried out PROVEAN analysis. PROVEAN predicted the SNP as 'Neutral' with a score of -0.297. To the best of our knowledge, this is the first genetic study of the SPRN gene in Korean native black goats.


Exploration of surgical blood pressure management and expected motor recovery in individuals with traumatic spinal cord injury.

  • Reza Ehsanian‎ et al.
  • Spinal cord‎
  • 2020‎

Retrospective analysis.


Completeness of manual data recording in the anaesthesia information management system: A retrospective audit of 1000 neurosurgical cases.

  • Sangeetha R Palaniswamy‎ et al.
  • Indian journal of anaesthesia‎
  • 2019‎

Anaesthesia information management system (AIMS) is increasingly implemented in many hospitals. Considering the capital cost involved in its installation and maintenance, it is important to evaluate its performance and adoptability by end users. This study assessed the completeness of manual data recording in the AIMS one year after its implementation and also evaluated potential predictors for completeness.


The impact of a new genus on the molecular phylogeny of Hemisphaeriini (Hemiptera, Fulgoromorpha, Issidae).

  • Songping Zhao‎ et al.
  • ZooKeys‎
  • 2019‎

A new genus, Retaldar gen. nov. of the family Issidae (Hemisphaeriinae, Hemisphaeriini) is described from Guangxi Province of China. A revised molecular analysis for the Hemisphaeriini based on partial sequences of 18S, 28S, COXI and Cytb, provides evidence for a new lineage within the subtribe Mongolianina. With two subgroups of genera now identified, the monophyly of Mongolianina is discussed from both a morphological and a molecular basis.


One new species and three newly recorded species of Neopallodes Reitter from China (Coleoptera, Nitidulidae, Nitidulinae).

  • XiaoXiao Chen‎ et al.
  • ZooKeys‎
  • 2019‎

One new species of the sap beetle genus Neopallodes, N. nigrescens sp. nov., is described and illustrated. New information on the distribution and illustrations of three species, N. dentatus Kirejtshuk, 1994, N. falsus Grouvelle, 1913 and N. vietnamicus Kirejtshuk, 1987, which are newly recorded from China, are also supplemented. A key to species of the genus Neopallodes from China is provided.


A new synonym for Zelia Robineau-Desvoidy, 1830 (Diptera, Tachinidae), the genus Opsozelia Townsend, 1919, with the description of three new species.

  • Rodrigo de Vilhena Perez Dios‎ et al.
  • ZooKeys‎
  • 2019‎

The monotypic tachinid genus Opsozelia Townsend, 1919 (Diptera: Tachinidae) is synonymized with ZeliaRobineau-Desvoidy 1830, syn. nov. The single species of Opsozelia, O. discalis Townsend, 1919, is redescribed as Zelia discalis, comb. nov., based on examination of the holotype from Guyana and additional material from Suriname, Brazil and Paraguay. Three new species of Zelia similar to Z. discalis are described from Brazil: Z. magna sp. nov., Z. guimaraesi sp. nov. and Z. formosa sp. nov. These four species are treated informally as the Zelia discalis species group. An identification key to the species of this species group is provided based on male specimens. Descriptions and illustrations are provided for the male terminalia of all species and for the female terminalia of one species, Z. guimaraesi.


The predictive value of dynamic monitoring of peripheral blood lymphocyte to monocyte ratio in patients with extranodal NK/T cell lymphoma.

  • Shengnan Zhang‎ et al.
  • Cancer cell international‎
  • 2019‎

To investigate the value of dynamic monitoring peripheral blood lymphocyte-to-monocyte (LMR) ratio in evaluating the treatment response and prognosis of patients with extranodal NK/T cell lymphoma (ENKTL).


Brief Mindfulness Meditation Improves Emotion Processing.

  • Ran Wu‎ et al.
  • Frontiers in neuroscience‎
  • 2019‎

Mindfulness-based interventions have previously been shown to have positive effects on psychological well-being. However, the time commitment, teacher shortage, and high cost of classic mindfulness interventions may have hindered efforts to spread the associated benefits to individuals in developing countries. Brief mindfulness meditation (BMM) has recently received attention as a way to disseminate the benefits of mindfulness-based interventions. Most existing BMM methods are adaptations of the classic approach. Few studies have investigated the mechanisms underlying the beneficial effects of BMM. We developed a 15-min BMM named JW2016, which is based on the core concepts of mindfulness, Anapanasati (breath meditation of Buddhist Vipassana), our practical experience, and the results of scientific reports on meditation. We investigated the effects of this BMM on mood and emotion processing in an effort to create an effective, convenient, safe, and standardized BMM method that could benefit individuals with limited time or money to devote to meditation. Forty-six healthy participants (aged 18-25 years) were randomly allocated to the BMM group (n = 23) or the emotional regulation education (ERE) control group (n = 23). Forty-two of the study participants cooperated fully in all measurements and interventions (one time daily for seven consecutive days). Mood was measured with the Centre for Epidemiological Studies-Depression scale (CES-D) and the State Anxiety Inventory (SAI). Emotion processing was evaluated by assessing performance on an emotion intensity task, an emotional memory task, and an emotional dot-probe task. After intervention, the BMM group, but not the ERE group, showed a significant decreases in emotional intensity in response to positive as well as negative emotional stimuli, response time for emotional memory, and duration of attention bias toward negative emotional stimuli. Negative effects on mood state were found in the ERE group but not in the BMM group. This study demonstrated that BMM may improve aspects of emotion processing such as emotion intensity, emotional memory, and emotional attention bias. JW2016 BMM may be an effective, convenient, safe and standardized way to help practitioners remain focused and peaceful without any negative effect on emotion.


Neuronal Cell-Intrinsic Defects in Mouse Models of Down Syndrome.

  • Alessandra Maria Adelaide Chiotto‎ et al.
  • Frontiers in neuroscience‎
  • 2019‎

Down Syndrome (DS) is the most common genetic disorder associated with intellectual disability (ID). Excitatory neurons of DS patients and mouse models show decreased size of dendritic field and reduction of spine density. Whether these defects are caused by cell autonomous alterations or by abnormal multicellular circuitry is still unknown. In this work, we explored this issue by culturing cortical neurons obtained from two mouse models of DS: the widely used Ts65Dn and the less characterized Ts2Cje. We observed that, in the in vitro conditions, axon specification and elongation, as well as dendritogenesis, take place without evident abnormalities, indicating that the initial phases of neuronal differentiation do not suffer from the presence of an imbalanced genetic dosage. Conversely, our analysis highlighted differences between trisomic and euploid neurons in terms of reduction of spine density, in accordance with in vivo data obtained by other groups, proposing the presence of a cell-intrinsic malfunction. This work suggests that the characteristic morphological defects of DS neurons are likely to be caused by the possible combination of cell-intrinsic defects together with cell-extrinsic cues. Additionally, our data support the possibility of using the more sustainable line Ts2Cje as a standard model for the study of DS.


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