240 research outputs found
Growth Plate Borderline Chondrocytes Behave as Transient Mesenchymal Precursor Cells
The growth plate provides a substantial source of mesenchymal cells in the endosteal marrow space during endochondral ossification. The current model postulates that a group of chondrocytes in the hypertrophic zone can escape from apoptosis and transform into cells that eventually become osteoblasts in an area beneath the growth plate. The growth plate is composed of cells with various morphologies; particularly at the periphery of the growth plate immediately adjacent to the perichondrium are “borderline” chondrocytes, which align perpendicularly to other chondrocytes. However, in vivo cell fates of these special chondrocytes have not been revealed. Here we show that borderline chondrocytes in growth plates behave as transient mesenchymal precursor cells for osteoblasts and marrow stromal cells. A single‐cell RNA‐seq analysis revealed subpopulations of Col2a1‐creER‐marked neonatal chondrocytes and their cell type–specific markers. A tamoxifen pulse to Pthrp‐creER mice in the neonatal stage (before the resting zone was formed) preferentially marked borderline chondrocytes. Following the chase, these cells marched into the nascent marrow space, expanded in the metaphyseal marrow, and became Col(2.3 kb)‐GFP+ osteoblasts and Cxcl12‐GFPhigh reticular stromal “CAR” cells. Interestingly, these borderline chondrocyte‐derived marrow cells were short‐lived, as they were significantly reduced during adulthood. These findings demonstrate based on in vivo lineage‐tracing experiments that borderline chondrocytes in the peripheral growth plate are a particularly important route for producing osteoblasts and marrow stromal cells in growing murine endochondral bones. A special microenvironment neighboring the osteogenic perichondrium might endow these chondrocytes with an enhanced potential to differentiate into marrow mesenchymal cells. © 2019 American Society for Bone and Mineral Research.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151266/1/jbmr3719_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151266/2/jbmr3719-sup-0001-Suppl_Info_JBMR_021819.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151266/3/jbmr3719.pd
An investigation into the relationship between thickness variations and manufacturing techniques of mouthguards.
BACKGROUND: The aim of this study was to measure the finished thickness of a single identical 4-mm EVA mouthguard model from a large fabricated sample group and to evaluate the degree of material thinning and variations during the fabrication process. MATERIALS AND METHODS: Twenty boxes were distributed to dental technician participants, each containing five duplicated dental models (n = 100), alongside 5 × 4 mm mouthguard blanks and a questionnaire. The mouthguards were measured using electronic callipers (resolution: ±0.01 mm) at three specific points. The five thickest and thinnest mouthguards were examined using a CT scanner to describe the surface typography unique to each mouthguard, highlighting dimensional thinning patterns during the fabrication process. RESULTS: Of the three measurement points, the anterior sulcus point of the mouthguard showed a significant degree of variation (up to 34% coefficient of variation), in finished mouthguard thickness between individuals. The mean thickness of the mouthguards in the anterior region was 1.62 ± 0.38 mm with a range of 0.77-2.80 mm. This variation was also evident in the occlusion and posterior lingual regions but to a lesser extent (up to 12.2% and 9.8% variations, respectively). CONCLUSION: This study highlights variability in the finished thickness of the mouthguards especially in the anterior sulcus region measurement point, both within and between individuals. At the anterior region measurement point of the mouthguard, the mean thickness was 1.62 mm, equating to an overall material thinning of 59.5% when using a single 4-mm EVA blank. This degree of thinning is comparative to previous single operator research studies
モルモット抗原吸入即時型気管支収縮反応後のプロプラノロール誘発気管支収縮モデルの作製とトロンボキサンA[2]および5-リポキシゲナーゼ代謝産物の関与
取得学位 : 博士(医学), 学位授与番号 : 医博甲第1140号, 学位授与年月日:平成6年4月30日,学位授与年:199
Study on the Pathogenesis of Foreign Body Granulomatous Inflammation in the Livers of Sprague-Dawley Rats
Focal granulomatous inflammation developed in the livers of five 10-week-old male
Sprague-Dawley rats. The characteristic features of this lesion were the
presence of foreign body multinucleated giant cells engulfing calcium deposits
and site-specific development in a fissure formed in a sub-lobation in the left
lobe or interlobar fissure of the medial lobe of the liver. To clarify the
pathogenesis of this lesion, rat livers showing abnormal sub-lobation or lobar
atrophy, rat livers in an acute dermal toxicity study and guinea pig livers in a
skin sensitization test were also examined histologically. Consequently, the
present lesion was considered to be a reactive change against calcium that was
dystrophically deposited in the area of hepatocellular necrosis due to delayed
circulatory disturbance caused by external pressure or extension force.
Granulomatous lesions like in the present cases should be differentiated from
those caused by evident exogenous pathogens such as chemicals or
microorganisms
Capture of Type 1 Diabetes–Susceptible HLA DR-DQ Haplotypes in Japanese Subjects Using a Tag Single Nucleotide Polymorphism
Charge Localization from Local Destruction of Antiferromagnetic Correlation in Zn-doped YBa2Cu3O7-d
The in-plane normal-state resistivity of Zn-doped YBa2Cu3O7-d single crystals
is measured down to low temperatures by suppressing superconductivity with
magnetic fields up to 18 T. Substitution of Cu with Zn in the CuO2 planes is
found to induce carrier localization at low temperatures in "clean" samples
with kF l > 5, where the mean free path l is larger than the electron wave
length and thus localization is not normally expected. The destruction of the
local antiferromagnetic correlation among Cu spins by Zn is discussed to be the
possible origin of this unusual charge localization.Comment: 4 pages of LaTeX (revtex and epsf) including 4 postscript figure
Zn-doping effect on the magnetotransport properties of Bi_{2}Sr_{2-x}La_{x}CuO_{6+\delta} single crystals
We report the magnetotransport properties of
Bi_{2}Sr_{2-x}La_{x}Cu_{1-z}Zn_{z}O_{6+\delta} (Zn-doped BSLCO) single crystals
with z of up to 2.2%. Besides the typical Zn-doping effects on the in-plane
resistivity and the Hall angle, we demonstrate that the nature of the
low-temperature normal state in the Zn-doped samples is significantly altered
from that in the pristine samples under high magnetic fields. In particular, we
observe nearly-isotropic negative magnetoresistance as well as an increase in
the Hall coefficient at very low temperatures in non-superconducting Zn-doped
samples, which we propose to be caused by the Kondo scattering from the local
moments induced by Zn impurities.Comment: 4 pages, 4 figures, final version (one reference added), published in
Phys. Rev.
Simple Model for the Variation of Superfluid Density with Zn Concentration in YBCO
We describe a simple model for calculating the zero-temperature superfluid
density of Zn-doped YBa_2Cu_3O_{7-\delta} as a function of the fraction x of
in-plane Cu atoms which are replaced by Zn. The basis of the calculation is a
``Swiss cheese'' picture of a single CuO_2 layer, in which a substitutional Zn
impurity creates a normal region of area around it as
originally suggested by Nachumi et al. Here is the zero-temperature
in-plane coherence length at x = 0. We use this picture to calculate the
variation of the in-plane superfluid density with x at temperature T = 0, using
both a numerical approach and an analytical approximation. For ,
if we use the value = 18.3 angstrom, we find that the in-plane
superfluid decreases with increasing x and vanishes near in the
analytical approximation, and near in the numerical approach.
is quite sensitive to , whose value is not widely agreed upon.
The model also predicts a peak in the real part of the conductivity,
Re, at concentrations , and low frequencies,
and a variation of critical current density with x of the form near percolation, where is the in-plane
superfluid density.Comment: 19 pages including 6 figures, submitted to Physica
A Wnt-mediated transformation of the bone marrow stromal cell identity orchestrates skeletal regeneration
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