675 research outputs found

    Studies on Hypoxia: XI. Long-Term Effects on the Epiphyseal Plate—A Histomeric and Radioautographic Study

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    Rats were exposed to hypoxia for one week. The mean thickness of epiphyseal plates from control rats was 430 micrometers (μm) which was reduced to 313 μm in hypoxic rats. Radioautographic incorporation of 3H-phenylalanine by connective tissue cells in hypoxic rats was reduced up to 38% in control rats.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66916/2/10.1177_00220345760550031301.pd

    Southern Hemisphere mid- and high-latitudinal AOD, CO, NO2, and HCHO: spatiotemporal patterns revealed by satellite observations

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    To assess air pollution emitted in Southern Hemisphere mid-latitudes and transported to Antarctica, we investigate the climatological mean and temporal trends in aerosol optical depth (AOD), carbon monoxide (CO), nitrogen dioxide (NO2), and formaldehyde (HCHO) columns using satellite observations. Generally, all these measurements exhibit sharp peaks over and near the three nearby inhabited continents: South America, Africa, and Australia. This pattern indicates the large emission effect of anthropogenic activities and biomass burning processes. High AOD is also found over the Southern Atlantic Ocean, probably because of the sea salt production driven by strong winds. Since the pristine Antarctic atmosphere can be polluted by transport of air pollutants from the mid-latitudes, we analyze the 10-day back trajectories that arrive at Antarctic ground stations in consideration of the spatial distribution of mid-latitudinal AOD, CO, NO2, and HCHO. We find that the influence of mid-latitudinal emission differs across Antarctic regions: western Antarctic regions show relatively more back trajectories from the mid-latitudes, while the eastern Antarctic regions do not show large intrusions of mid-latitudinal air masses. Finally, we estimate the long-term trends in AOD, CO, NO2, and HCHO during the past decade (2005-2016). While CO shows a significant negative trend, the others show overall positive trends. Seasonal and regional differences in trends are also discussed

    Reflection coefficient calculation of a feeder structure in a RLSA

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    RLSA(Radial line slot antenna) is slotted waveguide array antenna which is proposed for the DBS(Direct Broadcast from a Satellite) reception. Theoretically, it has lower conduction loss and higher effectiveness than the planar antenna using microstrip. DL-RLSA(Double-layered RLSA) uses radially inward travelling wave for the slot excitation in the double-layered radial line. The effectiveness of DL-RLSA is more than 75%(33.0~37dBi), which is two times as high effectiveness as other planar antenna. In spite of that advantage, SL-RLSA(Single-layered RLSA) is more popular because of the complex structure of DL-RLSA. But the radially outward travelling wave of SL-RLSA makes high tapering when the travelling wave approaches the aperture edge. To remove these troublesome thing, a effective feeder structure which has tilting rod is proposed in this paper. To find the optimum height and tilting angle of the feeder, the finitedifference time-domain(FDTD) method is employed. In other words, the simulation parameter of the FDTD algorithm is the dimension of feeder. Compared with the effectiveness of the conventional rod feeder structure, that of the proposed feeder structure in this paper is enhanced by 5dB

    Severe mitral regurgitation in a young female with pansinusitis and bronchiectasis

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    SummaryPrimary ciliary dyskinesia (PCD) is a disease characterized by symptoms of upper and lower respiratory tract infections due to abnormal structure and function of cilia.Cardiac involvement is characterized by situs inversus (Kartagener's syndrome in PCD) and other congenital cardiovascular abnormalities. We describe a 34-year-old female with a history of recurrent sinusitis and bronchiectasis but without situs inversus or other congenital cardiac anomalies in whom an association between mitral regurgitation secondary to myxoid degeneration and primary ciliary dyskinesia was suggested

    Light-chain amyloidosis presenting with rapidly progressive submucosal hemorrhage of the stomach

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    SummaryThe gastrointestinal tract is frequently in involved light-chain (AL) amyloidosis, but significant hemorrhagic complications are rare. A 71-year-old man presented to our hospital with dyspepsia and heartburn for 1 month. Gastroscopy revealed a large submucosal hematoma at the gastric fundus. Two days later, a follow-up gastroscopy indicated extensive expansion of the hematoma throughout the upper half of the stomach. The hematoma displayed ongoing expansion during the endoscopic examination, suggesting that rupture was imminent. Emergency total gastrectomy was performed, and amyloidosis was confirmed after examining the surgical specimen. Bone marrow examination revealed multiple myeloma, and serum immunoglobulin assay confirmed the diagnosis of myeloma-associated AL amyloidosis. At manuscript submission, the patient was doing well and was undergoing chemotherapy

    Induction of the Cytochrome P450 Gene CYP26 during Mucous Cell Differentiation of Normal Human Tracheobronchial Epithelial Cells

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    ABSTRACT In this study, the expression of CYP26 is examined in relation to retinoid-induced mucosecretory differentiation in human tracheobronchial epithelial (HTBE) cells and compared with that in human lung carcinoma cell lines. In HTBE cells, retinoic acid (RA) inhibits squamous differentiation and induces mucous cell differentiation as indicated by the suppression of transglutaminase I and increased expression of the mucin gene MUC2. The latter is accompanied by increased expression of CYP26 mRNA. RA is required but not sufficient to induce RAR␤, CYP26, and MUC2 mRNA because induction is only observed in confluent but not in logarithmic cultures, suggesting that additional factors are critical in their regulation. CYP26 mRNA can be induced by the RAR-selective retinoid 4-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-anthracenyl)-benzoic acid (TTAB) but not by the RXR-selective retinoid SR11217 or the antiactivator-protein 1-selective retinoid SR11302. RAR␣-, ␤-, and ␥-selective retinoids are able to induce CYP26; this induction is inhibited by the RAR␣-selective antagonist Ro41-5253. TTAB is able to induce CYP26 mRNA expression in only a few of the lung carcinoma cell lines tested. The lack of CYP26 induction in many carcinoma cell lines may relate to previously reported defects in the retinoid-signaling pathway. The induction of CYP26 correlated with increased metabolism of RA into 18-hydroxy-, 4-oxo-, and 4-hydroxy-RA. The latter metabolite was shown to be able to induce MUC2 and MUC5AC expression in HTBE cells. Our results demonstrate that in normal HTBE cells, CYP26 expression is closely associated with mucous cell differentiation and that many lung carcinoma cells exhibit increased RA metabolism and a defective regulation of CYP26
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