71 research outputs found
Effect of Revascularization on Headache Associated with Moyamoya Disease in Pediatric Patients
Episodic headache is common in childhood moyamoya disease (MMD). The onset, mechanism, cause of headache and the effect of revascularization surgery on headache are not yet clear. We studied 10 cases of children (7 boys and 3 girls) younger than 18 years who underwent revascularization for MMD between 2009 and 2013. We evaluated frequency of headache and cerebral blood flow changes by single photon emission computed tomography brain imaging with [I123]-labeled iofetamine (IMPSPECT) before and after surgery. Patients’ ages ranged from 0 to 15 years at onset and 2 to 17 years at the time of surgery, mean age being 6.7 and 8.0 years respectively. 9 of 10 patients presented with ischemic symptoms and 8 had headache. 5 patients underwent indirect bypass and 5 underwent combined direct and indirect bypass. Cerebral blood flow improvement was obtained in 14 of the 15 cerebral hemispheres revascularized mean follow-up duration was 32.9 months. All the patients had good outcomes with improvement of ischemic neurological deficits. Headache improved in 7 (87.5%) of 8 patients. Headache in pediatric moyamoya disease is associated with change in cerebral hemodynamics. Revascularization including combined direct bypass and indirect techniques may be required to reduce headache in patients with MMD
A Fully Implantable Wireless ECoG 128-Channel Recording Device for Human Brain–Machine Interfaces: W-HERBS
Brain–machine interfaces (BMIs) are promising devices that can be used as neuroprostheses by severely disabled individuals. Brain surface electroencephalograms (electrocorticograms, ECoGs) can provide input signals that can then be decoded to enable communication with others and to control intelligent prostheses and home electronics. However, conventional systems use wired ECoG recordings. Therefore, the development of wireless systems for clinical ECoG BMIs is a major goal in the field. We developed a fully implantable ECoG signal recording device for human ECoG BMI, i.e., a wireless human ECoG-based real-time BMI system (W-HERBS). In this system, three-dimensional (3D) high-density subdural multiple electrodes are fitted to the brain surface and ECoG measurement units record 128-channel (ch) ECoG signals at a sampling rate of 1 kHz. The units transfer data to the data and power management unit implanted subcutaneously in the abdomen through a subcutaneous stretchable spiral cable. The data and power management unit then communicates with a workstation outside the body and wirelessly receives 400 mW of power from an external wireless transmitter. The workstation records and analyzes the received data in the frequency domain and controls external devices based on analyses. We investigated the performance of the proposed system. We were able to use W-HERBS to detect sine waves with a 4.8-μV amplitude and a 60–200-Hz bandwidth from the ECoG BMIs. W-HERBS is the first fully implantable ECoG-based BMI system with more than 100 ch. It is capable of recording 128-ch subdural ECoG signals with sufficient input-referred noise (3 μVrms) and with an acceptable time delay (250 ms). The system contributes to the clinical application of high-performance BMIs and to experimental brain research
The Constrained Maximal Expression Level Owing to Haploidy Shapes Gene Content on the Mammalian X Chromosome.
X chromosomes are unusual in many regards, not least of which is their nonrandom gene content. The causes of this bias are commonly discussed in the context of sexual antagonism and the avoidance of activity in the male germline. Here, we examine the notion that, at least in some taxa, functionally biased gene content may more profoundly be shaped by limits imposed on gene expression owing to haploid expression of the X chromosome. Notably, if the X, as in primates, is transcribed at rates comparable to the ancestral rate (per promoter) prior to the X chromosome formation, then the X is not a tolerable environment for genes with very high maximal net levels of expression, owing to transcriptional traffic jams. We test this hypothesis using The Encyclopedia of DNA Elements (ENCODE) and data from the Functional Annotation of the Mammalian Genome (FANTOM5) project. As predicted, the maximal expression of human X-linked genes is much lower than that of genes on autosomes: on average, maximal expression is three times lower on the X chromosome than on autosomes. Similarly, autosome-to-X retroposition events are associated with lower maximal expression of retrogenes on the X than seen for X-to-autosome retrogenes on autosomes. Also as expected, X-linked genes have a lesser degree of increase in gene expression than autosomal ones (compared to the human/Chimpanzee common ancestor) if highly expressed, but not if lowly expressed. The traffic jam model also explains the known lower breadth of expression for genes on the X (and the Z of birds), as genes with broad expression are, on average, those with high maximal expression. As then further predicted, highly expressed tissue-specific genes are also rare on the X and broadly expressed genes on the X tend to be lowly expressed, both indicating that the trend is shaped by the maximal expression level not the breadth of expression per se. Importantly, a limit to the maximal expression level explains biased tissue of expression profiles of X-linked genes. Tissues whose tissue-specific genes are very highly expressed (e.g., secretory tissues, tissues abundant in structural proteins) are also tissues in which gene expression is relatively rare on the X chromosome. These trends cannot be fully accounted for in terms of alternative models of biased expression. In conclusion, the notion that it is hard for genes on the Therian X to be highly expressed, owing to transcriptional traffic jams, provides a simple yet robustly supported rationale of many peculiar features of X's gene content, gene expression, and evolution
Medical Examinations on School-Children of Oki Islands
A series of medical examinations was performed on school-children of Oki Is., Shimane Pref. in April, 1967. The investigations consisted of screening tests for acatalasemic gene carriers, ABO blood type tests, and ENT examinations. Results obtained are as follows: 1. ENT examinations and blood type tests showed average grade and value as those of other places of Japan. 2. Screening tests: Seven hypocatalasemic cases were found out among 4,831 children examined. Then, emergence of hypocatalasemia on Oki Is. was 0.15% , near to already known Japanese mean value
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