Dimethyl sulfoxide: interactions with aromatic hydrocarbons

Dimethyl sulfoxide (DMSO) enhanced the hypertaurinuria produced by benzene, chlorobenzene, and toluene in rats. Undiluted DMSO was more effective than DMSO diluted with water in potentiating the toxicity of benzene in both rats and mice. Supernatants (9000g) prepared from livers of rats treated with DMSO 24 hours earlier metabolized more benzene than those from control rats.     

Dimethyl sulfoxide: lens changes in dogs during oral administration

Oral administration of dimethyl sulfoxide to young dogs reduces relucency of the lens cortex, causing the normal central zone of lens to act as a strong biconvex lens.     

Hyperthermia protects against light damage in the rat retina

An increase in the synthesis of heat shock proteins that is induced in cells in vitro by hyperthermia or other types of metabolic stress correlates with enhanced cell survival upon further stress. To determine if a similar increase in stress tolerance could be elicited in vivo, rats were made hyperthermic, and then their retinas were tested for sensitivity to light damage. This treatment resulted in a marked decrease in photoreceptor degeneration after exposure to bright light as compared to normothermic animals. Concomitant with such protection was an increase in retinal synthesis of three heat shock proteins. Thus, a physiological rise in body temperature enhances the stress tolerance of nerve tissue, perhaps by increasing heat shock protein production.     

Adenosine triphosphate synthesis coupled to K+ influx in mitochondria

The influx of K+ into swollen mitochondria in the presence of valinomycin results in the synthesis of adenosine triphosphate in which approximately one H+ disappears per adenosine triphosphate synthesized. The synthesis is blocked by atractyloside but is insensitive to oligomycin and relatively insensitive to uncouplers.     

曲靖城区观赏植物冻害调查及分析

2008年2月6～15日曲靖城区出现了数10年未遇的冷冻天气,城区最低气温持续零度以下达10 d之久;2月27日至3月2日气温急剧下降,之后又急速回升的气象过程,对于不耐寒的热带观赏植物受冻害严重,甚至出现死亡.     

冻害的气象因子与胡柚产量的相关性分析

胡柚冻害是一个较复杂的过程,通过对胡柚冻害的气象因子分析,结果表明,冻害的气象因子不仅仅是冬季低温的强度、低温的持续时间,还包括当年前期秋季及冬季的降水量等.利用SPSS软件求解胡柚单位面积产量与冻害气象因子的相关性,得出上年度胡柚冻害的连续低于-3℃的天数与产量间相关性最显著,在连续3d以上时,可引起较大的减产,同时,利用各主要因子建立数学模型,预测胡柚的冻害程度与产量.     

碱性成纤维细胞生长因子对酒精中毒鼠小脑颗粒细胞存活的影响及作用机制的研究

目的：观察碱性成纤维细胞生长因子(bFGF)对鼠小脑颗粒细胞(CGC)存活的影响及作用机制。方法：通过光学显微镜观察bFGF、酒精及一氧化氮酶(NOS)抑制剂NG—硝基—L—精氨酸(N^G—nitro-L-arginine methyl ester,NAME)对CGC产生的影响。结果：bFGF能在无酒精的环境下，促进CGC的生存，使细胞数高于空白对照组(P＜0．01)，并能减少酒精对细胞的杀死，令CGC损失率较酒精空白对照组低(P＜0．01)，从而对细胞产生保护作用。但NAME却能抑制bFGF的作用。结论：bFGF通过一氧化氮酶促进CGC的存活并对抗酒精对CGC的毒性作用。     

Cell-free protein synthesizing system from yeast mitochondria

An active, cell-free protein synthesizing system has been obtained from yeast mitochondria. The system is stimulated by both polyuridylate and R17 RNA and is sensitive to inhibitors of bacterial protein synthesizing systems. A comparison is made between this system and that found in the cytoplasm of yeast.     

闽东北2003/2004年度冬季荔枝、龙眼冻害考察报告

从气象条件、立地条件、管理措施等方面分析了造成2003／2004年度冬季福鼎市荔枝、龙眼冻害的原因，探讨了今后福鼎发展荔枝、龙眼避冻应采取的一些措施。     

梨品种花期冻害差异及低温诱导花器官损伤形态学观察

为了解不同品种梨花期冻害及低温持续时间对花器官损伤的差异,在田间出现低温霜冻后,采用多点随机取样法调查了梨34个品种花期花朵冻害率,比较了树冠1.5 m以上与1.5 m以下花器官冻害差异及同一品种花序不同序位花朵受冻害情况;经-2℃低温处理1 h、2 h和4 h后,通过形态学观察研究低温处理时间对梨品种花器官损伤的影响。调查结果显示,梨树34个品种的花朵冻害程度存在很大差异,‘红香酥’、‘花长把’、‘红考密斯’等9个品种花期抗寒性较强,‘鸭梨’、‘朝鲜洋梨’、‘明月’等10个品种花期抗寒性较弱,其余15个品种花期抗寒能力中等;树冠1.5 m以上比1.5 m以下花器官冻害明显减轻;同一花序不同序位花朵冻害程度也呈现明显差别,低序位花较高序位花更易受冻;-2℃低温处理时间越长,花器官冻害发生率越高,其中雄蕊冻害发生率较雌蕊、花瓣低;‘砀山酥梨’、‘黄金梨’和‘黄花梨’花蕾期或盛花期花朵冻害离体诱导,证明开花期早的比开花晚的花器官遭受冻害更严重。研究结果为探索梨树花期冻害发生规律及品种抗冻机理提供了试验依据。     

Whole-genome shotgun sequencing of mitochondria from ancient hair shafts

Although the application of sequencing-by-synthesis techniques to DNA extracted from bones has revolutionized the study of ancient DNA, it has been plagued by large fractions of contaminating environmental DNA. The genetic analyses of hair shafts could be a solution: We present 10 previously unexamined Siberian mammoth (Mammuthus primigenius) mitochondrial genomes, sequenced with up to 48-fold coverage. The observed levels of damage-derived sequencing errors were lower than those observed in previously published frozen bone samples, even though one of the specimens was >50,000 14C years old and another had been stored for 200 years at room temperature. The method therefore sets the stage for molecular-genetic analysis of museum collections.     

Respiratory control: loss in mitochondria from diseased plants

Mitochondria from healthy oat seedlings oxidized succinate with good respiratory control and high ratios of adenosine diphosphate to oxygen. After treatment with victorin, the pathotoxin responsible for symptoms of Victoria blight of oats, susceptible seedlings yielded mitochondria with little respiratory control and lower ratios of adenosine diphosphate to oxygen. No such effects were obtained with victorin-treated resistant seedlings or when victorin was added directly to mitochondria from healthy susceptible or resistant plants. These data indicate that victorin-induced disease results in a reduction in efficiency of the energy-generating system of isolated mitochondria.     

线粒体磷脂酰甘油与作物幼苗冷敏感性

用差示扫描量热法分析了 6种作物幼苗线粒体极性脂和磷脂酰甘油 (PG)的热致相变。结果发现 ,抗冷性作物小麦发生相变的温度比其他冷敏感作物的低得多 ;小麦和花生线粒体 PG混合后 ,显著改变了各自的相变温度。线粒体 PG脂肪酸组成分析表明 ,脂肪酸饱和度决定其相变温度。线粒体 PG的脂肪酸饱和度与作物幼苗的冷敏感性相关     

Flunarizine protects neurons from death after axotomy or NGF deprivation

Systemically administered flunarizine enhanced neuronal survival in lumbar sensory ganglia in newborn rats after axotomy. Flunarizine-treated rats lost 71 percent fewer neurons than the untreated control rats at the end of 1 week. In cell culture, flunarizine at 30 to 40 microM also prevented neuronal death in nerve growth factor-dependent embryonic sensory and sympathetic neurons after the abrupt withdrawal of neurotrophic support. The drug may cause this effect by acting at an intracellular site, one distinct from its blockade of voltage-dependent calcium channels.     

Nonphosphorylating respiration of mitochondria from brown adipose tissue of rats

Mitochondria from brown adipose tissue of cold-acclimated rats (6 degrees C) oxidize alpha-ketoglutarate at a rate twice that of controls (26 degrees C). In both groups, however, the phosphorus: oxygen ratio with alpha-ketoglutarate never exceeded unity, and it is essentially zero with either succinate or alpha-glycerophosphate. Adenosine triphosphatase activity of these mitochondria is very low and it is not stimulated by 2,4-dinitrophenol. In addition, both respiration and phosphorylation are unaffected by adenosine diphosphate, 2,4-dinitrophenol, bovine serum albumin, or glutathione. Endogenous respiration of tissue slices is not stimulated by 2-4-dinitrophenol. It is suggested that brown fat mitochondria are not capable of oxidative phosphorylation, but do phosphorylate at the substrate level. Since these findings provide an unusual example of electron transport by means of an energetically nonconservative pathway, their significance to thermogenesis by brown adipose tissue is particularly emphasized.