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41.
Surgical pathologists are cautioned against the misinterpretation of immature dental tissues (dental papillae and follicles) and dental pulp as odontogenic tumors, especially odontogenic myxomas and fibromas. The close histologic similarity of the immature tissues to tumors may require a clinical-radiologic correlation with the histopathologic specimen in order to distinguish the locally aggressive tumors from innocuous dental tissues. 相似文献
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The multiple chemical sensitivity syndrome (MCS) is a novel constellation of symptoms in environmental medicine that has been extensively described and commented on in the USA. The main features of this syndrome are: multiple symptoms in different organ systems triggered by a variety of chemical substances, with relapses and exacerbations under certain precipitating circumstances at very low levels which do not cause any reactions in the population at large. There are no lab markers or specific investigative findings. This paper describes the historical development of the term MCS, its diagnostic criteria and pathophysiological aspects using 10 patient histories from our hospital. 相似文献
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R Niven R Pearlman T Wedeking J Mackeigan P Noker L Simpson-Herren JG Smith 《Canadian Metallurgical Quarterly》1998,87(11):1292-1299
The tissue biodistribution and expression of [33P]DNA-1-[2-[9-(Z)-octadecenoyloxy]ethyl]]-2-[8](Z)-heptadece nyl]-3 -[hydroxyethyl]imidazolinium chloride (DOTIM):cholesterol complexes and 33P-radiolabeled DNA expressing chloramphenicol acetyl transferase (CAT; 4.7 kB) were studied after intravenous (iv) injection in ICR mice. Mice were injected with 200 microL of complex containing DNA at 3 mg/kg or DNA alone. One group received 8 microCi of radioactivity and were sacrificed at 5 and 20 min, and 1, 2, 4 and 24 h post-dose (n = 4/time point). A second group received the equivalent of 3.9 microCi of radioactivity and were sacrificed at 20 min, and 2 and 24 h for subsequent whole body autoradiographic analysis (WBA; n = 2/time point). The tissue distribution of intact DNA was assessed by Southern blot at 24 h post-dose, whereas the integrity of complexes and DNA incubated in heparinized whole blood was studied separately. In further studies, the time course of expression in lung tissue over a 48-h period was examined, and the relative lung-expression of purified open circular (OC) versus supercoiled (SC) DNA at 24 h was evaluated. Approximately 42% of the radioactivity was found in the lungs 5 min after injection and about half this percentage was found in the liver. By 2 h, only 5% remained in the lungs, but 48% was present in the liver. No other tissue accumulated >5% of the dose throughout the duration of the study. WBA radiograms confirmed the tissue distribution results and highlighted significant accumulation of radioactivity in bone over time. Southern Blot analysis demonstrated intact DNA in many tissues 24 h after dosing. In contrast, the majority of DNA incubated in blood was degraded within 2 h, although the complexes afforded some protection relative to DNA alone. The OC DNA expressed equivalently to SC DNA in lung tissue (OC = 1035 +/- 183 pg; SC = 856 +/- 257 pg/mg soluble protein, n = 6, mean +/- SEM) at 24 h, and detectable levels of CAT were present within 2 h of dosing (21.3 +/- 7.2 pg, n >/= 8, mean +/- SD). The results confirm that DNA-DOTIM:cholesterol complexes are initially deposited in the lungs after iv administration. 相似文献
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TH Su JC Wang HH Tseng CP Chang TA Chang HJ Wei JG Chang 《Canadian Metallurgical Quarterly》1998,76(2):216-222
We show that mammalian cells can be stably transfected by a mechanical loading procedure in which cells are forced through a small opening in the presence of DNA. A suspension of cells and plasmid DNA in growth medium was passed up and down through a 30-gauge needle attached to a 1-ml syringe. Cells were immediately plated at appropriate densities for subsequent selection for stable expression of a marker gene. Two rodent cell lines, Chinese hamster ovary and mouse Ltk- cells, were successfully transfected with an efficiency of about one transfectant per 5 x 10(4) cells. The human HeLa cell line was transfected with a somewhat lower efficiency. Pluronic F-68, a detergent believed to aid in healing of membrane injuries, had no beneficial effect when present during the loading procedure. Successful transfection was accomplished using three different genes as selectable markers. Southern blotting analysis revealed that transfectants contained one or very few copies of the introduced DNA construct integrated into the genome. Several transfectants were demonstrated to remain stable for more than 20 generations of growth in the absence of selection. This procedure is fast, economical, and of general utility. 相似文献
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