Visualisation of cerebrospinal fluid flow patterns in albino Xenopus larvae in vivo

<p>Abstract</p> <p>Background</p> <p>It has long been known that cerebrospinal fluid (CSF), its composition and flow, play an important part in normal brain development, and ependymal cell ciliary beating as a possible driver of CSF flow has previously been studied in mammalian fetuses <it>in vitro</it>. Lower vertebrate animals are potential models for analysis of CSF flow during development because they are oviparous. Albino <it>Xenopus laevis </it>larvae are nearly transparent and have a straight, translucent brain that facilitates the observation of fluid flow within the ventricles. The aim of these experiments was to study CSF flow and circulation <it>in vivo </it>in the developing brain of living embryos, larvae and tadpoles of <it>Xenopus laevis </it>using a microinjection technique.</p> <p>Methods</p> <p>The development of <it>Xenopus </it>larval brain ventricles and the patterns of CSF flow were visualised after injection of quantum dot nanocrystals and polystyrene beads (3.1 or 5.8 μm in diameter) into the fourth cerebral ventricle at embryonic/larval stages 30-53.</p> <p>Results</p> <p>The fluorescent nanocrystals showed the normal development of the cerebral ventricles from embryonic/larval stages 38 to 53. The polystyrene beads injected into stage 47-49 larvae revealed three CSF flow patterns, left-handed, right-handed and non-biased, in movement of the beads into the third ventricle from the cerebral aqueduct (aqueduct of Sylvius). In the lateral ventricles, anterior to the third ventricle, CSF flow moved anteriorly along the outer wall of the ventricle to the inner wall and then posteriorly, creating a semicircle. In the cerebral aqueduct, connecting the third and fourth cerebral ventricles, CSF flow moved rostrally in the dorsal region and caudally in the ventral region. Also in the fourth ventricle, clear dorso-ventral differences in fluid flow pattern were observed.</p> <p>Conclusions</p> <p>This is the first visualisation of the orchestrated CSF flow pattern in developing vertebrates using a live animal imaging approach. CSF flow in <it>Xenopus </it>albino larvae showed a largely consistent pattern, with the exception of individual differences in left-right asymmetrical flow in the third ventricle.</p

Regional differences in the incidence of severe brain damage in survivors with cardiac disease and witnessed out-of-hospital cardiac arrest

Background: Brain damage can occur after out-of-hospital cardiac arrest (OHCA) leading to permanent disability.Aims: This study investigated the incidence of severe brain damage and associated risk factors in survivors with cardiac disease after OHCA.Methods: The Utstein database for Japan was used to identify 23,640 survivors with cardiac disease and witnessed OHCA between 2005 and 2012. Survivors were assessed at 1 month. Odds ratios (ORs) for the incidence of severe brain damage according to regional variables were determined with logistic regression analysis.Results: The incidence of severe brain damage was 37.3%. Automated external defibrillator use and cardiopulmonary resuscitation were associated with significant improvement in cerebral function; adrenaline administration and longer duration from request for transport until hospital arrival were associated with deterioration of cerebral function. Twenty of 47 prefectures showed significant ORs for the incidence of severe brain damage.Conclusion: Regional differences in the incidence of severe brain damage were found among survivors with cardiac disease and witnessed OHCA

Vitellogenin gene of the silkworm, Bombyx mori: Structure and sex-dependent expression

AbstractVitellogenin of Bombyx mori is a precursor of major yolk protein synthesized in the female fat body at larval—pupal ecdysis. The gene for B. mori vitellogenin is composed of seven exons interspersed by six introns. Developmental profile of the primary transcript of the gene indicated that the biosynthesis of B. mori vitellogenin is regulated transcriptionally in a sex- and stage-dependent manner in the fat body. The Arg-X-Arg-Arg sequence, which conforms to the recognition site of mammalian furin, occurs in a region just upstream of the putative proteolytic cleavage site of B. mori previtellogenin

Medical expenses for cilostazol to treat Alzheimer\u27s disease in Japan

Background: Cilostazol (CL) is an antithrombotic agent that was approved for prescribing under Japan’s national health insurance system in 2000. Clinical and experimental studies of CL to treat Alzheimer’s disease (AD) have been reported since 2009.Aims: To use the propensity score method to ascertain whether CL reduced medical expenses among patients with AD in a prefecture of Japan.Methods: Records of 21,181 patients with AD (6,484 males and 14,697 females) from April 2010 to March 2011 were selected from a claims database of the National Health Insurance and the Long-term Care Insurance systems in a prefecture in Japan. Covariates were patient characteristics, comorbidities, and drugs prescribed for AD, i.e. psychoactive agents, narcotics, anticonvulsants, or cholinesterase inhibitors. The outcome variable was medical expenses for the whole year.Results: The propensity score indicated that patients receiving CL had medical expenses ¥10.9 higher than those of patients not receiving CL.Conclusion: According to the propensity score method, CL did not efficiently reduce medical expenses for patients with AD based on claims data

Epigenetics of Vascular Formation during Zebrafish Hindbrain Development

The brain circulatory system is essential for the survival and development of the central nervous system in all vertebrates. Brain vessels form in a reproducible and evolutionarily conserved manner. In zebrafish, hindbrain vessels develop independently of the shear stress of blood flow but are regulated genetically. Epigenetics is another regulatory system regulating gene activation, but the epigenetic contribution to angiogenesis remains unclear. Here, we examine expression patterns of genes involved in SET1/mixed lineage leukemia (MLL) histone methyltransferase complexes. All mRNAs we tested as orthologs of molecules in the MLL complex were expressed throughout the central nervous system, including the hindbrain. We also show immunofluorescent staining of retinoblastoma-binding protein 5 (RBBP5) protein in the dorsal hindbrain, suggesting the possibility of differences in epigenetic state along the dorsalventral axis. Finally, we demonstrate histone methylation with non-methylated, dimethylated, and trimethylated types.Full-Length PaperBy a grant from Research Institute for Integrated Science, Kanagawa Universit

Photonic-crystal lasers with high-quality narrow-divergence symmetric beams and their application to LiDAR

Light detection and ranging (LiDAR) is a key technology for smart mobility of robots, agricultural and construction machines, and autonomous vehicles. However, current LiDAR systems often rely on semiconductor lasers with low-quality, large-divergence, and asymmetric beams, requiring high-precision integration of complicated lens systems to reshape the beam. Also, due to the broad linewidth and the large temperature dependence of their lasing spectrum, a bandpass filter with broad bandwidth must be used in front of the detector, so the detected signal is affected by noise from background light such as sunlight. These critical issues limit the performance, compactness, affordability, and reliability of the LiDAR systems. Photonic-crystal surface-emitting lasers (PCSELs) have attracted much attention as novel semiconductor lasers that can solve the issues of conventional semiconductor lasers owing to their capability of high-quality, very-narrow-divergence, and symmetric beam operation supported by broad-area band-edge resonance in their two-dimensional photonic crystal. In this paper, we show the progress and the state of the art of broad-area coherent PCSELs and their application to a time-of-flight (ToF) LiDAR system. We first review the progress of PCSELs made so far. Next, we show recent progress based on PCSELs with a double-lattice structure that enables higher-power and narrower-divergence operation while keeping a symmetric beam shape. By optimizing the double-lattice photonic crystal and the reflective properties of a backside distributed Bragg reflector (DBR), we achieve a high peak power of 10 W while maintaining a nearly diffraction-limited beam divergence of ∼0.1° (FWHM) from a 500 µm diameter resonator. Using this PCSEL, we construct a LiDAR system that uses no external lens system in its light source and demonstrate highly spatially resolved ToF sensing (measurement range of ∼20 m), which is appropriate for autonomous robots and factory automation