Toxaphene, but Not Beryllium, Induces Human Neutrophil Chemotaxis and Apoptosis via Reactive Oxygen Species (ROS): Involvement of Caspases and ROS in the Degradation of Cytoskeletal Proteins
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Abstract A microcolumn of alumina, activated at 250°C over night and deactivated with 2% water in an oven at 150°C, has shown better separation characteristics than similar ones, deactivated at room temperature, for a great number of organochlorine compounds, particularly with respect to multicomponent toxaphene and PCB. The microcolumn is a simple disposable Pasteur pipette. Three fractions are collected: one with PCB and DDE, one with toxaphene components having similar lipophilicity to DDT and the third, toxaphene components similar to DDD in lipophilicity. Two such toxaphene fractions give a better GLC-pattern than only one fraction. DDD and DDT, which interfere with the analysis of toxaphene can be eliminated, after their GLC analysis, from the “Toxaphene fractions” by nitration followed by reduction of the nitro compounds formed to their corresponding amines. Performance of the column using environmental samples showed that it is a useful tool in routine pesticide residue analysis, especially when toxaphene is present.
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Endrin
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The role of caspases in B lymphocyte cell death was investigated by using two broad spectrum inhibitors of the caspase family, Z‐Asp‐cmk and Z‐VAD‐fmk. They totally prevented spontaneous and drug‐induced apoptosis and inhibited the CPP32/caspase‐3‐like activity exhibited by apoptotic cells. However, the suppression of apoptosis was not associated with a long‐term increase of cell survival, but conversely, with a switch from apoptotic death to the necrotic form. These results strongly suggest that apoptosis and necrosis share common initiation pathways, the final issue being determined by the presence of an active caspase.
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瞄准：调查 resveratrol (物件) 的影响，一种营养的抗氧化剂，在在老鼠的 apoptosis 的抑制上主要神经原文化。方法：新生的 Sprague-Dawley 老鼠的有教养的外皮的神经原是有物件(0.1， 1.0，和 10.0 micromol/L ) 的 pretreated，有氧和葡萄糖的氧葡萄糖 deprivation/reperfusion (OGD/RP ) 在 d 被开始 10 在试管内。神经元 apoptosis 被流动血细胞计数决定，并且神经原的词法变化被一台电子显微镜观察。为机制研究，细胞内部的免费的钙集中([Ca2+] 我) 并且在神经原的 caspases-3 和 -12 的抄写被装载的 Fura 2/AM 和即时 RT-PCR 分别地检测。结果：OGD/RP 侮辱能处于神经原的 apoptotic 率导致增加(从 11.1% ～ 49.0%) ，并且在神经原得到一个明显的词法变化；有物件的预告的处理(0.1， 1.0，和 10.0 micromol/L，分别地) 分别地，显著地把 apoptosis 的提高的率归结为 41.7% ， 40.8% ，和 37.4% 并且改善神经元的词法损害。同样， OGD/RP 侮辱显然得到了提高的层次[Ca2+] 我和在神经原的 caspases-3 和 -12 mRNA 的表情。物件预告的处理显著地压抑神经元的反常举起[Ca2+] 我并且过去以一种集中依赖者方式的 caspases-3 和 -12 mRNA 的表示。结论：物件罐头稀释外皮的神经元 apoptosis 由 OGD/RP 导致了的老鼠。机制是，至少部分，由于钙超载的抑制并且过去 caspases-3 和 -12 的表示 mRNA。
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Both H2O2 and NO can act as apoptogens, triggering apoptosis in many cells. They are also well known inhibitors of caspases, essential enzymes in apoptosis. The differences between these two agents as apoptosis inducers and how caspases mediate apoptosis with these inhibitory agents is still unclear. Consistent with the previous reports, these two agents induced apoptosis accompanied by caspase activation with limitation of all apoptotic events for NO. It was found that NO-modified caspase-3 showed a slower recovery of its activity in the presence of the reducing agents compared to that of H2O2 modification. This is one possible cause of the limited apoptosis in the case of NO. Keywords: H2O2, NO, apoptosis, caspase
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Technical toxaphene (TT) was last used in commerce in about 1982. Any environmental exposure to toxaphene in this century is to environmentally degraded forms of toxaphene, termed weathered toxaphene. Several hundred chlorinated bornane congeners have been identified in technical toxaphene. The degradation of technical toxaphene to weathered toxaphene can result in various congener mixtures, but the primary mode of degradation is dechlorination. The U.S. Environmental Protection Agency (EPA) presently estimates the risk of exposure to toxaphene by relying upon rat and mouse toxicology studies performed on technical toxaphene. No adjustment is made for the dechlorination of toxaphene in the environment. The European Union (EU), however, has modeled toxaphene risks from eating fish with chlorinated bornane residues through a series of studies on toxaphene degraded by either ultraviolet light, or biodegradation in fish. The EU risk assessment relies upon rat liver studies in vivo and mouse in vitro studies on the inhibition of gap junction intercellular communication (GJIC). This article reviews the current state of knowledge of technical and weathered toxaphene toxicology. We discuss the various current methods and opportunities to advance the risk assessment of weathered toxaphene beyond the existing U.S. EPA assessment of technical toxaphene.
Toxaphene
Congener
Chlordane
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