We have developed a novel low-cost gamma-ray imaging Compton camera γI that has a high detection efficiency. Our motivation for the development of this detector was to measure the arrival directions ...of gamma rays produced by radioactive nuclides that were released by the Fukushima Daiichi nuclear power plant accident in 2011. The detector comprises two arrays of inorganic scintillation detectors, which act as a scatterer and an absorber. Each array has eight scintillation detectors, each comprising a large CsI (Tl) scintillator cube of side 3.5cm, which is inexpensive and has a good energy resolution. Energies deposited by the Compton scattered electrons and subsequent photoelectric absorption, measured by each scintillation counter, are used for image reconstruction. The angular resolution was found to be 3.5° after using an image-sharpening technique. With this angular resolution, we can resolve a 1m2 radiation hot spot that is located at a distance of 10m from the detector with a wide field of view of 1sr. Moreover, the detection efficiency 0.68cps/MBq at 1m for 662keV (7.6cps/μSv/h) is sufficient for measuring low-level contamination (i.e., less than 1μSv/h) corresponding to typical values in large areas of eastern Japan. In addition to the laboratory tests, the imaging capability of our detector was verified in various regions with dose rates less than 1μSv/h (e.g., Fukushima city).
Advantages and remaining issues of state-of-the-art m-plane freestanding GaN (FS-GaN) substrates grown by halide vapor phase epitaxy (HVPE) for m-plane InxGa1 − xN epitaxial film growth by ...metalorganic vapor phase epitaxy are described. Because of the low threading dislocation and basal-plane stacking fault densities, improved quantum efficiency and short radiative lifetime are achieved for the near-band-edge emission of 200-250 nm thick m-plane pseudomorphic InxGa1 − xN (x 0.14) epilayers. Values of full-width at half-maximum for the x-ray ω-rocking curves remain unchanged as the substrate values being 80 and 60 arcsec for the (100) diffraction with 〈0001〉 and azimuths, respectively, and 80 arcsec for the (102) diffraction. As the surface flatness is greatly improved, the In-incorporation efficiency (ηIninc) is lower than the cases for conventional c-plane growth and m-plane growths on defective GaN bases. The former originates from nonidentical surface kinetics, and the latter is due to the reduction in the area of inclined and tilted planes. Sub-micrometer-wide zonary patterns parallel to the c-axis and 2 μm long axis figure-of-eight patterns parallel to the a-axis are clearly visualized in the monochromatic cathodoluminescence (CL) intensity images. Because the spatio-time-resolved CL measurement reveals very little spatial variation of low-temperature radiative lifetime, the slight peak energy variation is interpreted to originate from nonidentical ηIninc for the growing surfaces exhibiting various miscut angles. The figure-of-eight patterns are ascribed to originate from the anisotropic, severe m-plane tilt mosaic along the a-axis of the GaN substrate, and the zonary patterns may originate from the m-plane tilt mosaic along the c-axis. Further reduction in the tilt and twist mosaics is necessary for HVPE of FS-GaN substrates, in order to grow homogeneous InGaN epilayers.
There is considerable interest in elucidating potential endogenously derived agonists of the vanilloid receptor and the role of anandamide in this regard has received considerable attention. In the ...present study, we have used an electrophysiological technique to investigate the mechanism of activation of vanilloid receptors in an isolated vagal preparation.
Both capsaicin and anandamide depolarized de‐sheathed whole vagal nerve preparations that was antagonized by the VR1 antagonist, capsazepine (P<0.05) whilst this response was unaltered by the cannabinoid (CB1) selective antagonist SR141716A or the CB2 selective antagonist, SR144528, thereby ruling out a role for cannabinoid receptors in this response.
The PKC activator, phorbol‐12‐myristate‐13‐acetate (PMA) augmented depolarization to both anandamide and capsaicin and this response was significantly inhibited with the PKC inhibitor, bisindolylmaleimide (BIM) (P<0.05).
The role of lipoxygenase products in the depolarization to anandamide was investigated in the presence of the lipoxygenase inhibitor, 5,8,11‐Eicosatriynoic acid (ETI). Depolarization to anandamide and arachidonic acid was significantly inhibited in the presence of ET1 (P<0.05). However, in the absence of calcium depolarization to anandamide was not inhibited by ETI.
Using confocal microscopy we have demonstrated the presence of vanilloid receptors on both neuropeptide containing nerves and nerves that did not stain for sensory neuropeptides.
These results demonstrate that anandamide evokes depolarization of guinea‐pig vagus nerve, following activation of vanilloid receptors, a component of which involves the generation of lipoxygenase products. Furthermore, these receptors are distributed in both neuropeptide and non‐neuropeptide containing nerves.
British Journal of Pharmacology (2002) 137, 39–48. doi:10.1038/sj.bjp.0704840
Summary
Idiopathic acquired generalized anhidrosis is a very rare disease of unknown pathogenesis. We report a 25‐year‐old man with acquired generalized anhidrosis due to occlusion of the coiled ...ducts. He did not have sweat secretion over the entire surface of the body, including the palms and soles. Sweat‐inducing stimuli provoked tingling pain on the skin. Pilocarpine iontophoresis on the forearm did not induce sweat secretion. Neurological examination did not reveal any abnormality in the central or peripheral nervous system. Skin biopsy showed that the coiled ducts were occluded by an amorphous eosinophilic substance. This amorphous eosinophilic substance was positive with periodic acid–Schiff (PAS) staining and was resistant to digestion by diastase. Electron microscopy demonstrated that the coiled ducts were completely occluded by an amorphous substance. The substance occluding the coiled ducts contained fibrous structures. These findings suggested that the acquired generalized anhidrosis in this patient was caused by occlusion of the coiled ducts by a PAS‐positive substance probably derived from dark cell granules.
The endogenous cannabinoid agonist, anandamide produced a modest contractile response in guinea‐pig isolated bronchus compared with the vanilloid receptor agonist capsaicin. The contractile response ...to both anandamide and capsaicin was inhibited by the vanilloid receptor antagonist, capsazepine. Furthermore, the NK2‐selective antagonist, SR48968 but not the NK1‐selective antagonist, SR140333 inhibited contractile responses to anandamide.
The contractile response to anandamide was abolished in tissues desensitized by capsaicin. However, anandamide failed to cross‐desensitize the contractile response to capsaicin.
The contractile response to anandamide was not significantly altered in the presence of the CB1 receptor antagonist, SR141716A, nor the amidase inhibitor, phenylmethylsulphonyl fluoride (PMSF) but was significantly increased in the presence of the neutral endopeptidase inhibitor, thiorphan.
The cannabinoid agonist, CP55,940 failed to significantly attenuate the excitatory non‐adrenergic non‐cholinergic (eNANC) response in guinea‐pig airways. In contrast, the ORL1 receptor agonist, nociceptin, significantly inhibited this response.
The results demonstrate that anandamide induces a modest contractile response in guinea‐pig isolated bronchus that is dependent upon the activation of vanilloid receptors on airway sensory nerves. However, cannabinoid receptors do not appear to play a role in this regard, nor in regulating the release of neuropeptides from airway sensory nerves under physiological conditions.
British Journal of Pharmacology (2001) 132, 1127–1135; doi:10.1038/sj.bjp.0703906
We developed an omnidirectional Compton camera for radioactive environmental monitoring which can visualize gamma rays with energy below 250 keV emitted from various radiopharmaceuticals used in ...nuclear medicine facilities to prevent occupational radiation exposure. An omnidirectional Compton camera based on high light yield scintillators CsI(Tl) or NaI(Tl) developed in our previous studies is a promising system for environmental radiation monitoring because it has a wide field of view and high sensitivity for sub-MeV gamma rays. However, its sensitivity rapidly decreases below 250 keV because photoelectric effect becomes more dominant than the Compton scattering process due to their large effective atomic numbers (approximately 50). Thus, CaF2(Eu) was adopted, which has both low effective atomic number (approximately 15) and high light yield. Four CaF2(Eu) crystals were arranged symmetrically to achieve a relatively uniform acceptance in all directions. Similarly, the detector rotation technique was adopted to suppress artificial patterns in a reconstructed gamma-ray image because of the small number of crystals. Through experiments in a laboratory and at a nuclear medicine facility, the capability of the camera to visualize gamma rays in energies from 250 keV to 60 keV with reasonable observation time for practical clinical use was confirmed.
ABSTRACT Blazars, one of the most extreme classes of active galaxies, constitute so far the largest known population of γ-ray sources, and their number is continuously growing in the Fermi catalogs. ...However, in the latest release of the Fermi catalog there is still a large fraction of sources that are classified as blazar candidates of uncertain type (BCUs) for which optical spectroscopic observations are necessary to confirm their nature and their associations. In addition, about one-third of the γ-ray point sources listed in the Third Fermi-LAT Source Catalog (3FGL) are still unassociated and lacking an assigned lower-energy counterpart. Since 2012 we have been carrying out an optical spectroscopic campaign to observe blazar candidates to confirm their nature. In this paper, the sixth of the series, we present optical spectroscopic observations for 30 γ-ray blazar candidates from different observing programs we carried out with the Telescopio Nazionale Galileo, William Herschel Telescope, Observatorio Astronómico Nacional, Southern Astrophysical Research Telescope, and Magellan Telescopes. We found that 21 out of 30 sources investigated are BL Lac objects, while the remaining targets are classified as flat-spectrum radio quasars showing the typical broad emission lines of normal quasi-stellar objects. We conclude that our selection of γ-ray blazar candidates based on their multifrequency properties continues to be a successful way to discover potential low-energy counterparts of the Fermi unidentified gamma-ray sources and to confirm the nature of BCUs.
FIBROBLAST migration, prolife ration, extracellular matrix protein synthesis and degradation, all of which play important roles in inflammation, are themselves induced by various growth factors and ...cytokines. Less is known about the interaction of these substances on lung fibroblast function in pulmonary fibrosis. The goal of this study was to investigate the effects of PDGF alone and in combination with IL–1β and TNF-α on the production of human lung fibroblast matrix metalloproteinases, proliferation, and the chemotactic response. The assay for MMPs activity against FITC labeled type I and IV collagen was based on the specificity of th e enzyme cleavage of collagen. Caseinolytis and gelatinolytic activities of secreted proteinases were analyzed by zymography. Fibronectin in conditioned media was measured using human lung fibronectin enzyme immunoas say. Cell prolife ration was measured by 3H-Thymidine incorporation as say. Cell culture supernatants were tested for PGE2 content by ELISA. Chemotactic activity was measured using the modified Boyden chamber. Matrix metalloproteinase as say indicated that IL– 1β, TNF-α and PDGF induced interstitial collagenase (MMP-1) production. MMP assay also indicated that IL-1β and TNF-α had inhibitory effects on MMP- 2,9(gelatinase A,B) production. Case in zymography confirmed that IL-1β stimulated stromlysin (matrix metalloproteinase 3; MMP-3) and gelatin zymography demons trated that TNF-α induced MMP-9 production in human lung fibroblast, whereas PDGF alone did not. PDGF in combination with IL-1β and TNF-α induced MMP-3 and MMP-9 activity, as demon-strated by zymography. PDGF stimulated lung fibroblast proliferation in a concentration-dependent manner, whereas IL-1b and TNF-α alone had no effect. In contrast, the prolife ration of human lung fibroblasts by PDGF was inhibited in the presence of IL-1β and TNF-α, and this inhibition was not a consequence of any elevation of PGE2. PDGF stimulated fibroblast chemotax is in a concentration-dependent manner, and this stimulation was augmented by combining PDGF with IL-1β and TNF-α. These findings suggested that PDGF differentially regulated MMPs production in combination with cytokines , and further that MMP assay and zymography had differential sensitivity for detecting MMPs . The presence of cytokines with PDGF appears to modulate the proliferation and chemotax is of human lung fibroblasts.
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