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991.
PURPOSE: To characterize computed tomographic (CT) findings of thoracic actinomycosis. MATERIALS AND METHODS: Chest CT scans and radiographs obtained in 22 patients with histopathologically proved thoracic actinomycosis were retrospectively reviewed. All patients were immunocompetent; they were aged 12-73 years (mean, 42.6 years; 14 male, eight female). CT findings were correlated with histopathologic findings in nine patients who underwent surgery (lobectomy [n = 8] or segmental resection [n = 1]). RESULTS: All of the lesions were unilateral, with an average diameter of 6.5 cm (range, 2-12 cm). Patchy air-space consolidation (n = 20) or a mass (n = 2) was seen on CT scans. Fifteen (75%) of the 20 patients with air-space consolidation had central areas of low attenuation (5-30 mm in diameter) within the consolidation. Thirteen of the 15 patients underwent contrast medium-enhanced CT. Ten (77%) of the 13 patients showed ring-like rim enhancement. Adjacent pleural thickening was seen in 16 patients (73%). At histopathologic examination, central low-attenuation areas at CT were seen as microabscesses with sulfur granules or a dilated bronchus that contained inflammatory cells and Actinomyces colonies. Peripheral enhancement of the low-attenuation areas was wall of the microabscess or surrounding parenchyma composed of granulation tissue rich in vascularity. CONCLUSION: Findings of chronic segmental air-space consolidation that contained low-attenuation areas with peripheral enhancement or adjacent pleural thickening at CT were suggestive of thoracic actinomycosis. 相似文献
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994.
AL Kuijpers JP Van Pelt M Bergers PJ Boegheim JE Den Bakker G Siegenthaler PC Van de Kerkhof J Schalkwijk 《Canadian Metallurgical Quarterly》1998,139(3):380-389
The imidazole derivative liarozole is a potent inhibitor of cytochrome P450-dependent 4-hydroxylation of endogenous all-trans retinoic acid, thereby increasing the levels of all-trans retinoic acid in both plasma and skin. As part of a large, double-blind, randomized clinical study, we investigated the cell biological alterations in uninvolved and lesional skin of 20 patients with severe plaque psoriasis, who were treated with either liarozole or acitretin. The extent and severity of the skin lesions, as recorded by the Psoriasis Area and Severity Index score, was significantly reduced (P =0.05) after 12 weeks of treatment in both the acitretin- and the liarozole-treated group. A significant decrease in the markers for inflammation (neutrophils), epidermal proliferation (Ki-67-positive cells), normal differentiation (transglutaminase) and abnormal differentiation [cytokeratin 16 and skin-derived antileucoproteinase (SKALP), also known as elafin] was seen in both groups. No significant differences were noted in clinical scores or cell biological scores between the liarozole- and acitretin-treated group. None of the markers returned to the levels seen in uninvolved skin or in normal human skin. The expression of epidermal fatty acid binding protein (E-FABP) was only minimally decreased after 12 weeks of treatment, a substantial part of the stratum spinosum remaining positive. SKALP levels in serum fell in both groups with similar kinetics and showed a statistically significant correlation with clinical scores. A remarkable finding in the uninvolved skin of patients treated with liarozole or acitretin was the distinct focal expression of SKALP in the granular layer and the expression of E-FABP in the spinous layers, which is not found in normal human skin. Although the mechanism of action differs fundamentally, liarozole and acitretin show similar effects with respect to clinical effects and cell biological changes in the lesional and non-lesional skin. 相似文献
995.
DM Stone M Hynes M Armanini TA Swanson Q Gu RL Johnson MP Scott D Pennica A Goddard H Phillips M Noll JE Hooper F de Sauvage A Rosenthal 《Canadian Metallurgical Quarterly》1996,384(6605):129-134
The protein Sonic hedgehog (Shh) controls patterning and growth during vertebrate development. Here we demonstrate that it binds Patched (vPtc), which has been identified as a tumour-suppressor protein in basal cell carcinoma, with high affinity. We show that Ptc can form a physical complex with a newly cloned vertebrate homologue of the Drosophila protein Smoothened (vSmo), and that vSmo is coexpressed with vPtc in many tissues but does not bind Shh directly. These findings, combined with available genetic evidence from Drosophila, support the hypothesis that Ptc is a receptor for Shh, and that vSmo could be a signalling component that is linked to Ptc. 相似文献
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997.
LM Canzoniero SL Sensi DM Turetsky MF Finley DW Choi JE Huettner 《Canadian Metallurgical Quarterly》1996,45(3):226-236
We have examined the control of calcium elevation by glutamate in neurons derived from the mouse P19 embryonal carcinoma cell line. Following transient exposure to retinoic acid, P19 cells differentiate into neurons that express both NMDA and non-NMDA glutamate receptor subtypes. Fluorescence videomicroscopy using the indicator fura-2 revealed concentration-dependent elevation in cytosolic calcium levels with exposure to NMDA or kainate. Replacement of extracellular sodium with N-methylglucamine significantly reduced the action of kainate. Exposure to high K+ medium also elicited an elevation of cytosolic calcium in P19 cells, which was partially inhibited by the calcium channel antagonist nimodipine. These experiments suggest that the elevation in calcium produced by kainate involves the activation of voltage-gated calcium channels as a consequence of membrane depolarization, in contrast to direct calcium entry through NMDA receptor channels. Whole-cell recordings revealed that P19 NMDA receptors were highly permeable to calcium (PCa/PNa = 5.6 +/- 0.2). In most cells, channels gated by kainate displayed low permeability to calcium; the median permeability ratio, PCa/PNa, was 0.053 (range 0.045 to 0.132). Activation of peak currents by NMDA, glycine, and kainate was half-maximal at 24 microM, 240 nM, and 81 microM, respectively. In addition, cadmium-sensitive currents through voltage-gated calcium channels were recorded in P19 cells bathed in barium/TEA chloride. Staining with antibodies directed against AMPA receptor subunits revealed wide-spread immunoreactivity for anti-GluR-B/C and anti-GluR-B/D. About half of the P19 cells were stained with antibodies selective for GluR-D but there was little or no immunoreactivity for the GluR-A subunit. 相似文献
998.
The use of uniformly 13C,15N-labeled RNA has greatly facilitated structural studies of RNA oligonucleotides by NMR. Application of similar methodologies for the study of DNA has been limited, primarily due to the lack of adequate methods for sample preparation. Methods for both chemical and enzymatic synthesis of DNA oligonucleotides uniformly labeled with 13C and/or 15N have been published, but have not yet been widely used. We have developed a modified procedure for preparing uniformly 13C,15N-labeled DNA based on enzymatic synthesis using Taq DNA polymerase. The highly efficient protocol results in quantitative polymerization of the template and approximately 80% incorporation of the labeled dNTPs. Procedures for avoiding non-templated addition of nucleotides or for their removal are given. The method has been used to synthesize several DNA oligonucleotides, including two complementary 15 base strands, a 32 base DNA oligonucleotide that folds to form an intramolecular triplex and a 12 base oligonucleotide that dimerizes and folds to form a quadruplex. Heteronuclear NMR spectra of the samples illustrate the quality of the labeled DNA obtained by these procedures. 相似文献
999.
The current paradigms for assessing fluorescence sensitivity on flow cytometers do not provide an adequate assessment of an instrument's ability to detect and measure weak fluorescence on stained particles. The capability to resolve dimly stained populations depends on two factors: the background noise (B), and the efficiency (Q) with which the fluorescence from the fluorochrome molecules are converted to photoelectrons. Any single statistical measure of fluorescence histogram distributions will be unable to uniquely characterize an instrument. Therefore, neither of the routinely used methods (detection threshold and delta channel) measure sensitivity completely and unambiguously. We show the limitations of these methods and propose that instrument sensitivity be characterized in terms of both background noise and detection efficiency in order to determine better the capability to detect and resolve weakly fluorescent particles. 相似文献
1000.