Ethyl pyruvate diminishes the inflammatory response to lipopolysaccharide infusion in horses

Reasons for performing the study: Endotoxaemia contributes to morbidity and mortality in horses with colic due to inflammatory cascade activation. Effective therapeutic interventions are limited for these horses. Ethyl pyruvate (EP), an anti‐inflammatory agent that alters the expression of proinflammatory cytokines, improved survival and organ function in sepsis and gastrointestinal injury in rodents and swine. Therapeutic efficacy of EP is unknown in endotoxaemic horses. Objectives: Determine the effects of EP on signs of endotoxaemia and expression of proinflammatory cytokines following administration of lipopolysaccharide (LPS) in horses. Methods: Horses received 30 ng/kg bwt LPS in saline to induce signs of endotoxaemia. Next, horses received lactated Ringer's solution (LRS), (n = 6), 150 mg/kg bwt EP in LRS, (n = 6), or 1.1 mg/kg bwt flunixin meglumine (FM), (n = 6). Controls received saline followed by LRS (n = 6). Physical examinations, behaviour pain scores and blood for clinical pathological testing and gene expression were obtained at predetermined intervals for 24 h. Results: Lipopolysaccharide infusion produced clinical and clinicopathological signs of endotoxaemia and increased expression of tumour necrosis factor alpha (TNFα), interleukin 6 (IL‐6) and IL‐8 (P<0.001) compared with controls. Leucopenia and neutropenia occurred in all horses that received LPS. Horses treated with EP and FM had significantly (P<0.0001) reduced pain scores compared with horses receiving LPS followed by LRS. Flunixin meglumine was significantly more effective at ameliorating fever compared with EP. Both EP and FM significantly diminished TNFα expression. Ethyl pyruvate significantly decreased, but FM significantly increased, IL‐6 expression. Neither EP nor FM altered IL‐8 expression. Conclusions and potential relevance: Ethyl pyruvate administered following LPS diminished the clinical effects of endotoxaemia and decreased proinflammatory gene expression in horses. Ethyl pyruvate suppressed expression of proinflammatory cytokines better than FM. However, FM was a superior anti‐pyretic compared with EP. Ethyl pyruvate may have therapeutic applications in endotoxaemic horses.     

Ethychlozate reduces acidity of loquat (Eriobotrya japonica) fruit

Ethychlozate (ethyl 5-chloro-1H-3-indazolylacetate, Figaron) was applied to 12-year-old ‘Jiefangzhong’ (a high-acid cultivar) loquat (Eriobotrya japonica) trees at 0 (control), 75, 150 and 250 mg L⁻¹ on March 19th, 90 days after flowering. To determine pulp titratable acidity (TA), organic acid concentration and acid-metabolizing enzyme activity, fruits were collected at 0, 13, 25, 42 and 49 days after treatments (DAT), when fruits were ripe. Malate was the major organic acid determining loquat pulp acidity. Ethychlozate was very effective in reducing pulp malate concentration, thus decreasing pulp acidity. The best result for reducing acidity (malate) was obtained when ethychlozate was applied at 250 mg L⁻¹. The ethychlozate-treated pulp showed lower phosphoenolpyruvate carboxylase (PEPC) and NAD-malate dehydrogenase (NAD-MDH) activities through the experimental period, but higher or similar NADP-malic enzyme (NADP-ME) from 25 to 49 DAT compared to non-sprayed control. The reduction in malate concentration in the ethychlozate-treated pulp was probably caused by decreased malate biosynthesis and increased malate degradation.     

Molecular approaches for enhancing sweetness in fruits and vegetables

The quality of fruits and vegetables is mainly dependant on the sweetness determined by the level of soluble sugars such as glucose, fructose and sucrose. Other fruit quality parameters include Brix content, acidity, aroma, color, size and shape. Total sugar content in fruits and vegetables is a function of genetic, nutritional, environmental and developmental factors. Understanding the factors controlling sweetness is important to design strategies for enhancing quality of fruits and vegetables. Modifying the activity of enzymes in carbohydrate metabolism such as sucrose synthase (SuSy), acid invertase, ADP-glucose pyrophosphorylase (AGPase), sucrose phosphate synthase (SPS) and sucrose transporters were found to influence carbohydrate partitioning and sucrose accumulation in sink tissues of several food crops. Plant based taste-modifying sweet proteins such as brazzein, cucurmin, mabinlin, monellin, miraculin, neoculin and thaumatin have potential application for developing transgenic plants to improve the sweetness and quality of fruits and vegetables. The present review envisages various cultural, breeding and molecular approaches used for enhancing sugar content and sweetness in fruits and vegetables.     

温度对蜕壳后期三疣梭子蟹能量代谢酶活力的影响

为研究温度对三疣梭子蟹雌蟹钙化过程中丙酮酸激酶(PK)、己糖激酶(HK)和琥珀酸脱氢酶(SDH)活力的影响,在实验室条件下设18、22、26 ℃ 3 个温度水平,分别在梭子蟹蜕壳后1、2、8、16 h及完全硬化5个时间点取样,测定其肝胰脏、肌肉和鳃中HK、PK、SDH的活力。结果显示:①与22 ℃条件下相比,高温(26 ℃)和低温(18 ℃)下三疣梭子蟹肌肉中PK的活力在蜕壳后1～8 h明显升高,说明高温和低温条件下梭子蟹肌肉中的糖酵解速率加大;而肝胰脏和鳃中的PK活力的峰值出现在梭子蟹蜕壳后1～2 h,表明蜕壳后1～2 h这2种组织中有较大的糖酵解速率;②3个温度水平下,梭子蟹肝胰脏中HK的活力随钙化过程的进行而降低,蜕壳后1～16 h的活力显著高于完全钙化时的活力,说明蜕壳后的梭子蟹肝胰脏对葡萄糖的利用能力逐渐减弱,而其鳃中HK活力的变化趋势与肝胰脏中相反,说明梭子蟹的鳃对葡萄糖的利用能力随钙化过程的进行而提高,这种差异可能与不同组织在梭子蟹钙化过程中对葡萄糖的利用能力不同有关;③梭子蟹肝胰脏中SDH的活力在3个实验温度下蜕壳后16 h内呈逐渐升高的趋势,说明肝胰脏在钙化过程中三羧酸循环作用逐渐加强。此外,其肌肉和鳃组织中SDH的活力在3个实验温度下的峰值均出现在前8小时,并且低温(18 ℃)的峰值明显低于高温(26 ℃),说明在这段钙化时间中,相对于低温而言,梭子蟹的肌肉和鳃中有氧代谢的加强在高温条件下更显著。在钙化过程中,低温条件下三疣梭子蟹的糖酵解作用没有明显的变化,而三羧酸循环有较明显的减弱趋势,其中三疣梭子蟹肌肉和鳃中SDH的活力明显低于高温条件,表明低温确实可以延长其蜕壳后的软壳时间。     

Interactive effect of monocrotophos and ammonium chloride on the freshwater fish Oreochromis mossambicus with reference to lactate/pyruvate ratio

Sublethal effect of monocrotophos (pesticide) and ammonium chloride (fertilizer) was studied in the freshwater fish Oreochromis mossambicus, with reference to carbohydrate metabolism for a period of 96 h. The glycogen content was analysed in liver and muscle, while the lactate and pyruvate were assessed in blood along with liver and muscle. The results revealed that the glycogen content was found to be decreasing. In contrast increase in the tissues lactate and pyruvate level was found in the fishes exposed to pesticide and fertilizer individually and in combinations. The combined effects of these chemicals were more toxic to carbohydrate metabolism than the effect produced by the individual chemicals. The results were tested to search for statistical significance. The calculated lactate and pyruvate ratio (L/P) indicated that the fishes were under chemical stress.     

Biotin in practical fish-meal based diet for Atlantic salmon Salmo salar L. fry

Groups of Atlantic salmon fry (0.19 g initial weight) were fed a fish-meal based starter diet with different supplements of biotin (0, 0.5, 1.0 and 1.5 mg biotin kg^–1) in triplicate tanks for 18 weeks. The basal diet contained 0.3 mg total biotin kg^–1. The experimental design included a negative control diet made by replacing 10% of the fish-meal with spray-dried raw hen's egg white.
Throughout the experimental period the fish grew to about 5 g and there were no significant differences in growth and mortality among the groups of fish fed the fish-meal diets. At the end of the experiment there were no significant differences in biotin level in the liver, while whole-body biotin concentrations correlated significantly with the dietary biotin concentrations. No significant increase in pyruvate carboxylase (PC) activity was found in livers from fish given different dietary levels of biotin. The control diet with egg white resulted in severe growth reduction and increased mortality compared with the other dietary groups. The concentrations of biotin in liver and whole body were decreased in fish fed egg white. Increased levels of glycogen and reduced PC activity in the liver were observed in this group after 18 weeks.
Histology of the gills showed no differences in appearance when fish were fed fish-meal based diets while the addition of egg white resulted in hypertrophy and hyperplasia of the gill tissue and extensive fusions of the secondary gill lamellae.
The results show that there is no need for supplemental biotin in practical fish-meal based diets for Atlantic salmon fry to achieve optimal growth, survival and maximal liver PC activity.     

甘蓝型油菜G3PDH和PK基因对氮肥的响应

氮肥作为植物生长最重要营养元素，其施用量的多少也是至关重要的。为了研究氮肥施用量对油菜含油量以及相关基因表达水平的影响，本研究以甘蓝型油菜宁油22作为材料，在0 kg/hm2、320 kg/hm2和640 kg/hm2三个不同氮肥水平下分别测定宁油22种子和角果皮的含油量，同时检测G3PDH和PK基因在不同氮肥水平下以及不同组织中的表达含量。结果发现，随着施氮量的增加，宁油22含油量下降，在0 kg/hm2和320 kg/hm2水平下下降不明显，在640 kg/hm2水平下明显下降，并且G3PDH和PK基因随着施氮量的增加，两个基因表达量均增强。本研究还分别分析了G3PDH和PK基因在种子跟角果皮中的比值以及开花30天后跟开花15天后的表达比，结果表明G3PDH基因在种子与角果皮的比值跟开花30天后跟15天后的表达比，均在640 kg/hm2水平下达到最高；PK基因在种子与角果皮中的比值在640 kg/hm2水平下达到最高，在开花30天后跟15天后的表达比在0kg/hm2水平下达到最大。     

猪肌肉组织中糖原酵解酶活性和PSE肉的相关性

本文用２０头猪的肌肉样品研究了肌肉纺织中丙酮酸激酶，磷酸果糖激酶，乳酸脱氢酶和ＰＳＥ肌肉的相关性。结果表明：屠宰后４５ｍｉｎ采取的肌肉中ＰＫ和ＰＦＫ活性在正常骨肉和ＰＳＥ肌肉之间差异极显著（Ｐ＜０．０１）。并且ＰＫ与常规肉质指标ｐＨ值，系水力和光反射值存在显著相关性（Ｐ＜０．０５，Ｐ＜０．０１，Ｐ＜０．０１）。     

锥虫中的糖体

锥虫有许多生化特性，其中之一就是糖体，血液型锥虫由于线粒体发育不全，生存所需的能量只能通过葡萄糖在糖体中进行酵解来获得。糖体中含有与糖酵解有关的酶。１ 摩尔葡萄糖在糖体中经过酵解可获得２ 摩尔ＡＴＰ。糖体的特殊结构组成使得糖体可提供足够的能量供锥虫生存     

INFLUENCE OF ARBUSCULAR MYCORRHIZAL FUNGI AND AMMONIUM:NITRATE RATIOS ON GROWTH AND PUNGENCY OF SPRING ONION PLANTS

A pot experiment was carried out to study the growth and pungency of Allium fisutulosum grown in Perlite as affected by colonization by the arbuscular mycorrhizal (AM) fungi Glomus etunicatum, Glomus vesiforme, and by ammonium (NH⁺ ₄ ):nitrate (NO^? ₃ ) ratios of 5:95, 50:50, and 95:5 in 4 mM solutions. Plants were grown in a greenhouse for 20 weeks and then harvested. In general, NH⁺ ₄ :NO^? ₃ ratio of 50:50 supplied resulted in the highest shoot dry weight regardless of non-mycorrhizal and mycorrhizal plants while the effect of inoculation treatment on plant biomass was not significant. The plant sulfur (S) concentrations were usually higher in mycorrhizal plants than controls irrespective of nitrogen ratio and therefore inoculation with G. etunicatum increased the enzyme produced pyruvic acid (EPY) while inoculation with G. versiforme decreased the EPY compared with the non-mycorrhizal plants. In general, shoot pungency was lowest when NH⁺ ₄ :NO^? ₃ ratio of 95:5 supplied irrespective of mycorrhizal treatment. Colonization by both AM fungi made a substantial contribution to spring onion sulfur nutrient status but show different way on flavor characteristics of host plants.