Transporter-mediated ecdysteroid trafficking across cell membranes: A novel target for insect growth regulators

Ecdysteroids are a class of steroid hormones in arthropods that control molting and metamorphosis through interaction with intracellular nuclear receptors. In contrast to the extensive literature describing their biosynthetic pathways and signaling components, little has been known about how these hormones are traveling into and out of the cells through lipid bilayers of the cell membranes. Recently, a series of studies conducted in the fruit fly Drosophila melanogaster revealed that membrane transporters have critical functions in trafficking ecdysteroids across cell membranes, challenging the classical simple diffusion model of steroid hormone transport. Here we summarize recent advances in our understanding of membrane transporters involved in ecdysteroid signaling in Drosophila, with particular focus on Ecdysone Importer (EcI) that is involved in ecdysteroid uptake in peripheral tissues. We then discuss the potential advantage of EcI blockers as a novel pest management tool as compared to classical insect growth regulators.     

HPLC法测定复方防己口服液中粉防己碱和防己诺林碱的含量

为了用HPLC法同时测定复方防己口服液中粉防己碱和防己诺林碱的含量.采用Diamonsil C 18柱(5μm,4.6 mm×250 mm),以乙腈-0.2％磷酸水溶液-三乙胺(63∶37∶0.05)为流动相,流速为1.0 mL/min,检测波长282 nm的液相检测方法.结果表明,在此色谱条件下,粉防己碱和防己诺林碱的分离良好,分别在20.52 ～ 205.2μg/mL和17.84 ～ 178.4 μg/mL浓度范围内峰面积与浓度呈良好的线性关系.按外标法以峰面积计算进行测定,粉防已碱和防己诺林碱的平均回收率分别为98.15％和97.35％,RSD分别为1.39％和1.90％.表明该方法简便,快速,准确,适用于防已散中粉防己碱和防己诺林碱的含量测定.     

番茄基因工程的研究进展

文中概述了近几年来番茄基因工程方面的研究进展。其中番茄基因组精细序列分析的完成是这一领域得以快速发展的基础。在育种方面,利用转基因技术生产出了具有各种抗性的番茄植株,获得了具有优良品质的新品种。同时,基因工程手段拓展了番茄在医学上的应用。目前研究人员已利用番茄生产药用蛋白、抗体、口服疫苗、病毒转基因番茄疫苗,并且对番茄红素的研究有望推动对癌症基因疗法的研究。总之,利用基因工程手段,有望使番茄成为集治疗、营养和免疫于一身的新型蔬菜。     

Oral Bioavailability of Quercetin in Horses

Quercetin, one of the most abundant flavonoids in plants, is discussed with respect to health-promoting effects like antioxidative and anti-inflammatory properties. Although most claims regarding biological effects of flavonoids are based on in vitro and ex vivo studies, the use of flavonoid-containing supplements in humans and companion animals has increased in recent years. Flavonoid-containing supplements are also offered for pet and livestock nutrition. However, any systemic effect of a substance within a living subject depends on its bioavailability. Therefore, the aim of the present study was to gain information on the oral bioavailability of quercetin in horses. Four Icelandic horses with a mean body weight (BW) of 315 ± 25 kg (mean ± standard error [SEM]) were fed a test meal (crimped oats 1 g/kg BW) with the addition of quercetin (20 mg/kg BW). Blood samples were collected directly from the jugular vein before and after ingestion of the test meal for 24 hours, and flavonoid content was analyzed by high-performance liquid chromatography. Quercetin was the main metabolite in plasma with intact flavonol structure after β-glucuronidase/sulfatase treatment of blood samples. The area under the plasma concentration–time curve of quercetin accounted for 88% of total flavonols. Forty-seven percent of the quercetin detected in plasma after ingestion of the test meal was not conjugated. In addition to quercetin, the quercetin derivatives isorhamnetin (methylated) and kaempferol were detected in plasma. Although quercetin is orally bioavailable in horses, similar to other monogastric species, the plasma metabolite pattern differs from those found in species investigated previously (rat, dog, pig, and human).     

A Randomized Blinded Crossover Clinical Trial to Determine the Effect of an Oral Joint Supplement on Equine Limb Kinematics,Orthopedic, Physiotherapy,and Handler Evaluation Scores

Despite the range of oral joint supplements available, there has been very limited research into their efficacy. The study aimed to determine the effect of an oral joint supplement on limb kinematics, orthopedic, physiotherapy, and handler evaluation in horses. Supplement S or placebo P was fed to 24 horses for 21 days each in a random order. Horses were evaluated at days 0 (baseline), 21 (after first treatment), and 42 (after second treatment). Assessments included the following: clinical orthopedic evaluation for straight line/lunging circle in walk and trot; high-speed motion capture determined hindlimb kinematics for straight-line trotting; grading of limb range of motion (ROM) and muscle tone based on standardized physiotherapy criteria; handler grading of specific criteria during pasture, groundwork, and ridden exercise. Effect of treatment, sequence, limb, and interactions were investigated using linear-mixed models. S was associated with significantly lower lameness grade in a straight line (P = .001) and circle (P = .010), with individual horses improving up to 2/10 grades over P/baseline. S was associated with significantly improved ROM and muscle tone. Ridden/groundwork scores were significantly higher with S compared to P/baseline. With S, horses were graded significantly higher for “ease of movement” at pasture compared with P/baseline. For horses with hindlimb lameness, S was associated with significantly greater tarsal flexion than baseline (4.2% greater, P < .020) or P (2.7% greater, P < .037). S was associated with less lameness and improved physiotherapy scores, ridden/groundwork scores, and pasture “ease of movement.” Increased midstance tarsal flexion of lame limbs may indicate improved mobility/comfort during peak loading, supporting a positive effect of S.     

从双黄连口服液分析中兽药提取制剂的应用前景

和中兽药非提取制剂（主要是散剂）相比,虽然中兽药提取制剂具有明显优点,但片面于讲究现代化制剂工艺和指标性质量标准,导致生产成本增高,失去了经济动物应用价值。针对经济动物临床应用特点,中兽药提取制剂应遵循中兽医药客观特点及发展规律,既要满足药剂学要求,又要保持中兽医药特色,即要充分利用现代先进制剂技术,还有保持制剂成本符合经济规律。     

基于农村生源高职生英语口语教学的创新攻略

论述了提高英语口语能力的必要性与迫切性,以及目前高职非英语专业农村生源学生的口语能力相对低下的问题,并提出了提高非英语专业农村高职生英语口语能力的若干创新举措。     

Dimethoate induced biochemical perturbations in rat pancreas and its attenuation by cashew nut skin extract

The significant antiradical activity of cashew skin extract was previously described. In this investigation, the extent of protection offered by cashew nut skin extract (CSE) against the damage induced in rat pancreas by sub chronic doses dimethoate (DM), an organophosphorous pesticide was studied. Rats were supplemented with CSE at 20 mg/kg b.w./d after a daily dose of DM at 40 mg/kg/d b.w. for 2 months. Weekly random blood glucose, oral glucose tolerance test (OGTT); pancreatic damage markers like amylase and lipase; oxidative damage markers such as reactive oxygen species generated, extent of lipid peroxidation, host antioxidant defenses like reduced glutathione (GSH); GSH-dependent enzyme activities viz., glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR); free radical scavenger enzymes viz., catalase and superoxide dismutase (SOD); xenobiotic metabolizing enzymes like DT-diaphorase and NADPH-diaphorase were measured in the four different groups namely (1) control, (2) DM treated, (3) CSE supplemented, (4) CSE supplements following DM treatment. Random blood glucose levels increased significantly on exposure to DM compared to that in control rats (119 ± 5 mg/dl vs. 92 ± 4 mg/dl), while the blood glucose levels in CSE supplemented rats were comparable to that of controls. DM treated rats exhibited impaired glucose tolerance at the end of two months as indicated by OGTT, while DM treated rats with CSE supplements showed normal glucose tolerance. Pancreatic specific marker enzymes like amylase and lipase in serum were restored to normalcy in rats supplemented with CSE following treatment with DM which otherwise was increased in the DM treated rats. Distinctly lower levels of GSH, increased levels of ROS, higher extent of lipid peroxidation, along with alterations in antioxidant enzymes and increase in xenobiotic metabolizing enzymes were evident in pancreas of DM treated rats. However, CSE supplement ameliorated the biochemical alterations in the pancreatic milieu in DM treated rats. Treatment with CSE significantly protected rat pancreas from injury, thus ameliorating and restoring tissue antioxidant status and also conferring normal glucose tolerance. The active components present in cashew skin extract can perhaps be effective in reducing the extent of pancreatic injury and in overcoming tissue damage caused by exposure to dimethoate.