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Pathogenic strains of Sporothrix schenkii may show triangular spores, whose angular shape is maintained by a tiebeam effect in the inner cell wall structure. This difference in wall structure lies adjacent to a folded and possibly more active part of the spore cytoplasm. The supposed generation of asci in old cultures was simulated by the death of hyphae which are reinvaded by intrahyphal growth with intrahyphal spore production, while true asci were not seen. 相似文献
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Autoradiographic model experiments with 67Ga and 99mTc 总被引:1,自引:0,他引:1
Summary In order to evaluate the feasibility to localize correctly 67Ga citrate and 99mTc pertechnetate in tissues, the resolution of these radioactive compounds were measured in a model system using four different autoradiographic techniques, wet as well as dry.Wet autoradiographic techniques gave an almost complete loss of 67Ga. In deparaffinized sections of fixed and paraffin-embedded tissue the remaining 67Ga, which was probably bound to proteins, gave a resolution of 2.6 . 99mTc was either completely lost in wet techniques or the procedure could not be performed at all because of the very short half life of 99mTc.The resolution of 67Ga in a dry autoradiographic technique (according to Stumpf) was 6.9 and the resolution of 99mTc 22.6 .The technique in which frozen sections are thawed on dry film and consequently dryed, gave slightly better resolutions than the dry technique (according to Stumpf) with 67Ga as well as 99mTc.It is concluded that for the histological localization of 67Ga and 99mTc a dry technique is required. However, the use of a wet technique can be considered, provided a loss of the radioisotope is acceptable and the procedure is controlled by a dry technique. 相似文献
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Plant desiccation and protein synthesis: an in vitro system from dry and hydrated mosses using endogenous and synthetic messenger ribonucleic Acid 下载免费PDF全文
The conditions and requirements for an in vitro protein synthesizing system from the moss Tortula ruralis are outlined. Using this system the effects of desiccation, achieved quickly or slowly, were studied. Slowly dried moss retained fewer polyribosomes on desiccation but more active ribosomes than rapidly dried moss. Even in the completely desiccated moss the polyribosomes and/or free ribosomes present have retained their synthetic capacities. On rehydration, the slowly dried moss resumed protein synthesis more quickly than moss previously desiccated rapidly. Moss ribosomes are cycloheximide sensitive and chloramphenicol insensitive and thus the major protein synthesis occurs within the cytoplasm on rehydration. Extracted polyribosomes per se can withstand desiccation to a significant extent, suggesting that protection by the cytoplasm might not be necessary. The aquatic moss Hygrohypnum luridum can retain polyribosomal and ribosomal activity during desiccation, but this decreases greatly on rehydration. 相似文献
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