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1. Apoptosis as the mechanism of cell death induced by a new cytotoxic and anticancer agent (N.C.1213) was investigated by morphological and biochemical criteria in human Jurkat T leukemia cells.2. The effect of N.C.1213 on the survival of Jurkat T, LV-50, H-9, and Molt-3 cells was measured. Jurkat T cells exhibited the highest response, with less than 10% of the cells remaining viable after exposure to 10 M N.C.1213 for a 24 hr period. All other cell cultures were also affected but to a lesser extent.3. With the use of a fluorescence microscope, several morphological features characteristic of apoptosis such as condensed chromatin and apoptotic bodies were indemnified in Jurkat T cells after exposure to N.C.1213 and melphalan. The results indicated that melphalan was more cytotoxic than N.C.1213 as shown by the dye exclusion test. However, N.C.1213 showed a greater apoptotic index than melphalan. The IC50 of N.C.1213 in Jurkat T cells was determined to be 3.5 M 4. A DNA ladder (fragmentation of DNA into multimers of approximately 200 base pairs), which is one characteristic feature of apoptosis, was not detected when Jurkat T cells were exposed to N.C.1213. Hence it is probable that the key morphological events in apoptosis observed in the present experimental conditions precede the internucleosomalcleavage of DNA.  相似文献   
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Background  

Recombinant protein production is universally employed as a solution to obtain the milligram to gram quantities of a given protein required for applications as diverse as structural genomics and biopharmaceutical manufacture. Yeast is a well-established recombinant host cell for these purposes. In this study we wanted to investigate whether our respiratory Saccharomyces cerevisiae strain, TM6*, could be used to enhance the productivity of recombinant proteins over that obtained from corresponding wild type, respiro-fermentative strains when cultured under the same laboratory conditions.  相似文献   
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Background

Avoidance of allergens is still recommended as the first and best way to prevent allergic illnesses and their comorbid diseases. Despite a variety of attempts there has been very limited success in the area of environmental control of allergic disease. Our objective was to identify a non-invasive, non-pharmacological method to reduce indoor allergen loads in atopic persons' homes and public environments. We employed a novel in vivo approach to examine the possibility of using aluminum sulfate to control environmental allergens.

Methods

Fifty skin test reactive patients were simultaneously skin tested with conventional test materials and the actions of the protein/glycoprotein modifier, aluminum sulfate. Common allergens, dog, cat, dust mite, Alternaria, and cockroach were used in the study.

Results

Skin test reactivity was significantly reduced by the modifier aluminum sulfate. Our studies demonstrate that the effects of histamine were not affected by the presence of aluminum sulfate. In fact, skin test reactivity was reduced independent of whether aluminum sulfate was present in the allergen test material or removed prior to testing, indicating that the allergens had in some way been inactivated.

Conclusion

Aluminum sulfate was found to reduce the in vivo allergic reaction cascade induced by skin testing with common allergens. The exact mechanism is not clear but appears to involve the alteration of IgE-binding epitopes on the allergen. Our results indicate that it may be possible to diminish the allergenicity of an environment by application of the active agent aluminum sulfate, thus producing environmental control without complete removal of the allergen.  相似文献   
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Abstract: Growth periodicity is a phenomenon occurring in fossil and modern corals. The most apparent feature is growth banding, and environmental changes are broadly accepted as controls on this phenomenon. If environment controls the growth, then all corallites within a colony should repeat the same growth pattern, as individuals are clones and must have shared the same environment. A study on several species of Alveolitidae (Anthozoa, Tabulata) from the Late Devonian (Early Frasnian) of the Holy Cross Mountains (Poland) shows that the growth pattern varies between neighbouring individuals within the same corallum. This contradicts observations of closely related Favositida as demonstrated on Pachyfavosites sp. from the Givetian of Avesnois, France, where neighbouring individuals repeat the same pattern. Therefore, environmental control on growth rhythm in Alveolitidae can be excluded; the causes of differences between individuals remain unknown.  相似文献   
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