53 research outputs found
Decrease in excitatory neurons, astrocytes and proliferating progenitors in the cerebral cortex of mice lacking exon 3 from the Fgf2 gene
<p>Abstract</p> <p>Background</p> <p>The <it>Fgf2 </it>gene is expressed in the brain neuroepithelium during embryonic development and in astroglial cells throughout life. Previous knockout studies suggested that FGF2 plays a role in the proliferation of neural progenitors in the embryonic cerebral cortex. These studies exclusively used knockout alleles lacking the <it>Fgf2 </it>exon 1. However, the description of putative alternative exons located downstream from the canonical exon 1 raised the possibility that alternatively spliced transcripts may compensate for the lack of the canonical exon 1 in the <it>Fgf2 </it>-/- mice.</p> <p>Results</p> <p>We generated and characterized a new line of Fgf2 knockout mice lacking the expression of exon 3, which is conserved in all <it>Fgf2 </it>transcripts and contains essential heparin and receptor binding interfaces. The expression of <it>Fgf2 </it>exon 3 was prevented by inserting a transcriptional STOP cassette in the <it>Fgf2 </it>genomic locus. These mice demonstrate a phenotype in the adult neocortex characterized by decreased density and number of cortical excitatory neurons and astrocytes, which is virtually identical to that of the <it>Fgf2 </it>-/- mice lacking exon 1. In addition, we also show that the <it>Fgf2 </it>exon 3 knockout mice have decreased proliferation of precursors in the adult cerebral cortex, which had not been previously investigated in the other mutant lines.</p> <p>Conclusion</p> <p>The results demonstrate that the phenotype of two completely different <it>Fgf2 </it>KO mouse lines, lacking exon 1 or exon 3, is remarkably similar. The combined results from these KO models clearly indicate that FGF2 plays a role in cortical cell genesis during embryonic development as well as in adulthood. Thus, FGF2 may be required for the maintenance of the pool of adult cortical progenitor cells.</p
Sodium Channelopathy Underlying Familial Sick Sinus Syndrome With Early Onset and Predominantly Male Characteristics
Background-Sick sinus syndrome (SSS) is a common arrhythmia often associated with aging or organic heart diseases but may also occur in a familial form with a variable mode of inheritance. Despite the identifcation of causative genes, including cardiac Na channel (SCN5A), the pathogenesis and molecular epidemiology of familial SSS remain undetermined primarily because of its rarity. Methods and Results-We genetically screened 48 members of 15 SSS families for mutations in several candidate genes and determined the functional properties of mutant Na channels using whole-cell patch clamping. We identifed 6 SCN5A mutations including a compound heterozygous mutation. Heterologously expressed mutant Na channels showed loss-of-function properties of reduced or no Na current density in conjunction with gating modulations. Among 19 family members with SCN5A mutations, QT prolongation and Brugada syndrome were associated in 4 and 2 individuals, respectively. Age of onset in probands carrying SCN5A mutations was signifcantly less (mean±SE, 12.4±4.6 years; n=5) than in SCN5A-negative probands (47.0±4.6 years; n=10; P<0.001) or nonfamilial SSS (74.3±0.4 years; n=538; P<0.001). Meta-analysis of SSS probands carrying SCN5A mutations (n=29) indicated profound male predominance (79.3%) resembling Brugada syndrome but with a considerably earlier age of onset (20.9±3.4 years). Conclusions-The notable pathophysiological overlap between familial SSS and Na channelopathy indicates that familial SSS with SCN5A mutations may represent a subset of cardiac Na channelopathy with strong male predominance and early clinical manifestations
Influencing factors on serum 25-hydroxyvitamin D3 levels in Japanese chronic hepatitis C patients
Memory Immune Responses against Pandemic (H1N1) 2009 Influenza Virus Induced by a Whole Particle Vaccine in Cynomolgus Monkeys Carrying Mafa-A1*052∶02
We made an H1N1 vaccine candidate from a virus library consisting of 144 ( = 16 HA×9 NA) non-pathogenic influenza A viruses and examined its protective effects against a pandemic (2009) H1N1 strain using immunologically naïve cynomolgus macaques to exclude preexisting immunity and to employ a preclinical study since preexisting immunity in humans previously vaccinated or infected with influenza virus might make comparison of vaccine efficacy difficult. Furthermore, macaques carrying a major histocompatibility complex class I molecule, Mafa-A1*052∶02, were used to analyze peptide-specific CD8+ T cell responses. Sera of macaques immunized with an inactivated whole particle formulation without addition of an adjuvant showed higher neutralization titers against the vaccine strain A/Hokkaido/2/1981 (H1N1) than did sera of macaques immunized with a split formulation. Neutralization activities against the pandemic strain A/Narita/1/2009 (H1N1) in sera of macaques immunized twice with the split vaccine reached levels similar to those in sera of macaques immunized once with the whole particle vaccine. After inoculation with the pandemic virus, the virus was detected in nasal samples of unvaccinated macaques for 6 days after infection and for 2.67 days and 5.33 days on average in macaques vaccinated with the whole particle vaccine and the split vaccine, respectively. After the challenge infection, recall neutralizing antibody responses against the pandemic virus and CD8+ T cell responses specific for nucleoprotein peptide NP262-270 bound to Mafa-A1*052∶02 in macaques vaccinated with the whole particle vaccine were observed more promptly or more vigorously than those in macaques vaccinated with the split vaccine. These findings demonstrated that the vaccine derived from our virus library was effective for pandemic virus infection in macaques and that the whole particle vaccine conferred more effective memory and broader cross-reactive immune responses to macaques against pandemic influenza virus infection than did the split vaccine
More Accurate Knowledge Search in Technological Development for Robust Parameter Design
Purpose: The causality search Taguchi (CS-T) method was proposed to support system selection in a robust parameter design. However, the target of the analysis is likely to be quasi-experimental data. This can be difficult to analyse with the CS-T method. Therefore, this study proposes a new analysis approach that can perform a more accurate knowledge search by applying the instrumental variable.
Methodology/Approach: Using the CS-T method, appropriate knowledge search is difficult with quasi-experimental data, including endogeneity. We examined an analytical process that addresses the endogeneity between mechanism and output by utilizing the control and noise factors that constitute the mechanism as instrumental variables.
Findings: The results show that 1) the proposed method has sufficient practical accuracy, even for quasi-experimental data including endogeneity; and 2) the extracted mechanism is less likely to fluctuate depending on the number of experimental conditions used. Moreover, we can clarify the position of the CS-T and proposed methods in system selection.
Research Limitation/Implication: We perform estimation under the assumption that the threshold is known. However, the extracted mechanism may change depending on the threshold; this requires discussing how to determine them.
Originality/Value of paper: Technological development requires a high degree of engineer sophistication. However, this study’s analytical process allows conducting more accurate knowledge search in a realistic and systematic way without requiring a high level of engineer input
Study on Likelihood-Ratio-Based Multivariate EWMA Control Chart Using Lasso
Purpose: When applying exponentially weighted moving average (EWMA) multivariate control charts to multivariate statistical process control, in many cases, only some elements of the controlled parameters change. In such situations, control charts applying Lasso are useful. This study proposes a novel multivariate control chart that assumes that only a few elements of the controlled parameters change.
Methodology/Approach: We applied Lasso to the conventional likelihood ratio-based EWMA chart; specifically, we considered a multivariate control chart based on a log-likelihood ratio with sparse estimators of the mean vector and variance-covariance matrix.
Findings: The results show that 1) it is possible to identify which elements have changed by confirming each sparse estimated parameter, and 2) the proposed procedure outperforms the conventional likelihood ratio-based EWMA chart regardless of the number of parameter elements that change.
Research Limitation/Implication: We perform sparse estimation under the assumption that the regularization parameters are known. However, the regularization parameters are often unknown in real life; therefore, it is necessary to discuss how to determine them.
Originality/Value of paper: The study provides a natural extension of the conventional likelihood ratio-based EWMA chart to improve interpretability and detection accuracy. Our procedure is expected to solve challenges created by changes in a few elements of the population mean vector and population variance-covariance matrix
Coordinate expression of Fgf8, Otx2, Bmp4, and Shh in the rostral prosencephalon during development of the telencephalic and optic vesicles
Previous studies suggest that Fgf8 has a key role in regulating vertebrate development. In the rostral head of the embryonic chicken, there are increasing numbers of separate Fgf8 domains; these are present in tissues that appear to have previously expressed Otx2. As Fgf8 expression becomes established, Otx2 expression weakens, but remains in cells abutting the Fgf8 expression domain. These Fgf8 expression domains are closely associated with tissues expressing Bmp4 and Shh. Based on analogy with the embryonic limb, we suggest that Fgf8, Bmp4 and Shh function together in patterning regions of the embryonic head. Gene expression changes are particularly prominent in 14–21 somite stage embryos in the rostral forebrain, during early morphogenesis of the telencephalic and optic vesicles, when several new interfaces of Fgf8, Bmp4 and Shh are generated. To gain insights into the functions of fibroblast growth factor 8 (FGF8) in the embryonic forebrain, we studied the effects of implanting beads containing this protein in the dorsal prosencephalon of embryonic day 2 chicken embryos. Ectopic FGF8 had profound effects on morphogenesis of the telencephalic and optic vesicles. It disrupted formation of the optic stalk and caused a transformation of the pigment epithelium into neural retina. Within the telencephalon, FGF8 beads frequently induced a sulcus that had features of an ectopic rostral midline. The sulcus separated the telencephalon into rostral and caudal vesicles. Furthermore, we present evidence that FGF8 can regulate regionalization of the prosencephalon through inhibition of Otx2 and Emx2 expression.
Thus, these experiments provide evidence that FGF8 can regulate both morphogenesis and patterning of the rostral prosencephalon (telencephalic and optic vesicles). FGF8 beads can induce midline properties (e.g. a sulcus) and can modulate the specification and differentiation of adjacent tissues. We suggest that some of these effects are through regulating the expression of homeobox genes (Otx2 and Emx2) that are known to participate in forebrain patterning.This work was supported by the research grants to J.L.R.R. from: Nina Ireland, the Don and Linda Carter Foundation, Human Frontiers Science Program and K02 MH01046-01.Peer reviewe
Elastic properties of indium nitrides grown on sapphire substrates determined by nano-indentation: In comparison with other nitrides
The hardness of wurtzite indium nitride (α-InN) films of 0.5 to 4 μm in thickness was measured by the nano-indentation method at room temperature. After investigation of crystalline quality by x-ray diffraction, the hardness and Young’s modulus were determined to be 8.8 ± 0.4 and 184 ± 5 GPa, respectively, for the In (0001)- and N
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-growth faces of InN films. The bulk and shear moduli were then derived to be 99 ± 3 and 77 ± 2 GPa, respectively. The Poisson’s ratio was evaluated to be 0.17 ± 0.03. The results were examined comprehensively in comparison with previously reported data of InN as well as those of other nitrides of aluminum nitride and gallium nitride. The underlying physical process determining the moduli and hardness was examined in terms of atomic bonding and dislocation energy of the nitrides and wurtzite zinc oxide
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