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821.
We report a case of Guillain-Barré syndrome and associated cytomegalovirus infection during pregnancy. A 15-year-old black adolescent had progressive ascending paralysis and vague sensory symptoms during week 10 of her first pregnancy. Diagnosis of Guillain-Barré syndrome was confirmed by electrophysiologic findings consistent with acute demyelinating polyradiculoneuropathy. A mild elevation of anti-GM1 antibodies was also detected. The patient improved with plasmapheresis treatment; however, fetal death occurred 10 weeks later. Cytomegalovirus placentitis was confirmed histologically. Acute demyelinating polyneuropathy during pregnancy warrants consideration of a concomitant, primary maternal and fetal cytomegalovirus infection. 相似文献
822.
We consider the inverse problem of thermoelasticity for an isotropic medium containing a cavity of unknown shape and subjected
to the action of mechanical and thermal loads. Nonlinear equations are deduced for the geometric parameters of an ellipsoidal
equistressed cavity. Similar relations for mechanical loads obtained by the other authors follow from the constructed equations
as special cases. The numerical analysis is performed and the relationship between the values of the loads and the parameters
of the cavity is investigated. The stresses on the equistressed surface of the cavity are found and the influence of temperature
on the relationship between the parameters of loads and the geometric characteristics of the equistressed cavity is analyzed.
__________
Translated from Problemy Prochnosti, No. 1, pp. 121–131, January–February, 2007. 相似文献
823.
L Alhonen A Karppinen M Uusi-Oukari S Vujcic VP Korhonen M Halmekyt? DL Kramer R Hines J J?nne CW Porter 《Canadian Metallurgical Quarterly》1998,273(4):1964-1969
A recently generated transgenic mouse line having activated polyamine catabolism due to systemic overexpression of spermidine/spermine N1-acetyltransferase (SSAT) was used to isolate primary fetal fibroblasts as a means to further elucidate the cellular consequences of activated polyamine catabolism. Basal levels of SSAT activity and steady-state mRNA in the transgenic fibroblasts were about approximately 20- and approximately 40-fold higher than in non-transgenic fibroblasts. Consistent with activated polyamine catabolism, there was an overaccumulation of putrescine and N1-acetylspermidine and a decrease in spermidine and spermine pools. Treatment with the polyamine analogue N1,N11-diethylnorspermine (DENSPM) increased SSAT activity in the transgenic fibroblasts approximately 380-fold, whereas mRNA increased only approximately 3-fold, indicating post-mRNA regulation. SSAT activity in the nontransgenic fibroblasts increased approximately 200-fold. By Western blot, enzyme protein was found to increase approximately 46 times higher in the treated transgenic fibroblasts than non-transgenic fibroblasts: a value comparable to 36-fold differential in enzyme activity. With DENSPM treatment, spermidine pools were more rapidly depleted in the transgenic fibroblasts than in nontransgenic fibroblasts. Similarly, transgenic fibroblasts were much more sensitive to DENSPM-induced growth inhibition. This was not diminished by co-treatment with an inhibitor of polyamine oxidase, suggesting that growth inhibition was due to polyamine depletion per se as opposed to oxidative stress. Since the two fibroblasts were genetically identical except for the transgene, the various metabolic and growth response differences are directly attributable to overexpression of SSAT. 相似文献