21 research outputs found

    Regionalized choroid plexus-cerebrospinal fluid factors and effect of DNA Ligase IV deficiency in the developing mammalian brain

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    Fundamental to mammalian brain development is the integration of cell intrinsic and extrinsic signals that direct the proliferation and differentiation of neural stem cells. Precise expression of transcription factors together with other intracellular components instruct progenitor cell fate, whereas interaction with extracellular signaling factors refines this process. We have elucidated the composition of the cerebrospinal fluid that is the source of multiple extrinsic cues during brain development. The choroid plexus, a highly vascularized tissue located in each ventricle of the brain, actively secretes cerebrospinal fluid. By RNA sequencing, we obtained transcriptome data on the choroid plexi from lateral and fourth ventricles of the mouse brain and discovered that they include transcripts unique to each tissue. Transcription factor expression in the macaque and human choroid plexi suggests that positional identities of these tissues are conserved in the primate brain. Based on transcriptional results, we defined the choroid plexus secretome, a prediction of secreted factors from the choroid plexus. By quantitative mass spectrometry, we detected proteins secreted by each choroid plexus, and comparison of these proteomic results with transcriptional profiling suggests that choroid plexus transcriptomes contribute to availability of regionalized cerebrospinal fluid factors during development. In the second part of my dissertation research, I studied the role of DNA repair mechanisms in regulating neural stem cells. These studies focused on DNA LigaseIV, an essential component of DNA double-stranded break repair, during cerebral cortical development. Deficiency of LigaseIV activity caused by a missense mutation leads to LigaseIV syndrome, in which a key clinical feature is microcephaly. Using the Lig4 R278H mouse mutant, we found increased cell death in the developing cortex, contributing to reduced cortical thickness and cellularity in the anterior cerebral cortex. These results indicate that DNA LigaseIV is essential for proper cortical development. Together, these findings illustrate the complexity of regulatory mechanisms that guide brain development, requiring the integration of mechanisms from within and outside the cell. We have investigated two such mechanisms, extrinsic cues from regionalized cerebrospinal fluid and DNA LigaseIV. These results should provide greater insight into mechanisms of normal brain development and neuropathological states.2017-11-02T00:00:00

    The Cerebrospinal Fluid Provides a Proliferative Niche for Neural Progenitor Cells

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    Cortical development depends on the active integration of cell autonomous and extrinsic cues, but the coordination of these processes is poorly understood. Here, we show that the apical complex protein Pals1 and Pten have opposing roles in localizing the Igf1R to the apical, ventricular domain of cerebral cortical progenitor cells. We found that the cerebrospinal fluid (CSF), which contacts this apical domain, has an age-dependent effect on proliferation, much of which is attributable to Igf2, but that CSF contains other signaling activities as well. CSF samples from patients with glioblastoma multiforme show elevated Igf2 and stimulate stem cell proliferation in an Igf2-dependent manner. Together, our findings demonstrate that the apical complex couples intrinsic and extrinsic signaling, enabling progenitors to sense and respond appropriately to diffusible CSF-borne signals distributed widely throughout the brain. The temporal control of CSF composition may have critical relevance to normal development and neuropathological conditions

    ZNHIT3 is defective in PEHO syndrome, a severe encephalopathy with cerebellar granule neuron loss

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    Progressive encephalopathy with oedema, hypsarrhythmia, and optic atrophy (PEHO) syndrome is an early childhood onset, severe autosomal recessive encephalopathy characterized by extreme cerebellar atrophy due to almost total granule neuron loss. By combining homozygosity mapping in Finnish families with Sanger sequencing of positional candidate genes and with exome sequencing a homozygous missense substitution of leucine for serine at codon 31 in ZNHIT3 was identified as the primary cause of PEHO syndrome. ZNHIT3 encodes a nuclear zinc finger protein previously implicated in transcriptional regulation and in small nucleolar ribonucleoprotein particle assembly and thus possibly to pre-ribosomal RNA processing. The identified mutation affects a highly conserved amino acid residue in the zinc finger domain of ZNHIT3. Both knockdown and genome editing of znhit3 in zebrafish embryos recapitulate the patients' cerebellar defects, microcephaly and oedema. These phenotypes are rescued by wild-type, but not mutant human ZNHIT3 mRNA, suggesting that the patient missense substitution causes disease through a loss-of-function mechanism. Transfection of cell lines with ZNHIT3 expression vectors showed that the PEHO syndrome mutant protein is unstable. Immunohistochemical analysis of mouse cerebellar tissue demonstrated ZNHIT3 to be expressed in proliferating granule cell precursors, in proliferating and post-mitotic granule cells, and in Purkinje cells. Knockdown of Znhit3 in cultured mouse granule neurons and ex vivo cerebellar slices indicate that ZNHIT3 is indispensable for granule neuron survival and migration, consistent with the zebrafish findings and patient neuropathology. These results suggest that loss-of-function of a nuclear regulator protein underlies PEHO syndrome and imply that establishment of its spatiotemporal interaction targets will be the basis for developing therapeutic approaches and for improved understanding of cerebellar development.Peer reviewe

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

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    Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Rare Phenomenon of Extracranial Metastasis of Glioblastoma

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    Indocyanine green lymphangiography-guided liposuction in breast cancer-related lymphedema treatment - patient selection and technique

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    Aim: The rationale of using liposuction to treat lymphedema is that the chronic inflammatory process of lymphedema results in fat hypertrophy. The authors describe the technique of indocyanine green lymphangiography-guided liposuction, its rationale, and our patient selection criteria for better clinical outcomes.Methods: Thirty-two patients underwent liposuction for breast cancer-related lymphedema. Indocyanine green lymphangiography was performed prior to liposuction. For patients without linear and splash patterns in indocyanine green lymphangiography, circumferential liposuction was performed liberally. For patients who had linear or splash patterns, liposuction was not performed at regions with remaining functional lymphatic vessels. Outcomes were assessed using circumferential reduction rate.Results: At a mean follow-up of 24.5 ± 6.5 months, all (100%) patients had a reduction in limb circumferences after liposuction. The mean circumference reduction rate was 67.6% ± 27.9%.Conclusion: Liposuction is a valuable treatment for breast cancer-related lymphedema. We believe patients with fat predominant lymphedema are the best candidates for liposuction

    Different Orders of Combined Upper- and Lower-Body Resistance Exercise Induce Different Pulse Wave Reflection Responses induce in Resistance-Trained Young Women

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    Varying the orders of UL and LU resistance exercise (RE) has been shown to induce different cardiovascular responses in active men. However, various orders of upper- and lower-body RE on pulse wave reflection in resistance-trained young women is unknown. PURPOSE: To evaluate the pulse wave reflection in resistance-trained young women based on the effects of different orders of upper- and lower-body RE. METHODS: Twelve resistance-trained young women (22±2 yrs) completed the study. Pulse wave reflection was assessed at rest, 10 (R1), and 20 (R2) minutes after either upper- and lower-body RE (UL) or lower- and upper-body RE (LU) for 3 sets of 10 repetitions at 75% 1-repetition maximum with 90-second and 2-minute rests between sets and exercises, respectively. The upper- and lower-body RE consisted of latissimus dorsi pulldown and incline chest press, and knee extension and knee flexion, respectively. RESULTS: Exercise volume between UL and LU was similar (p=0.387). LU significantly (pCONCLUSION: These data suggest that different orders of combined upper- and lower-body RE induce different responses on pulse wave reflection. In addition, LU significantly elevated PWR than UL which might place greater workload to the heart in active men. Starting at upper-body RE then finishing at lower-body RE may be a more cardio-protective workout regime
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