新兽药研发流程及安全性评价

编者语：随着地标升国标工作的进行,我国兽药产品严重同质化的时代已经来临,因此,新产品的研究开发是企业能够在未来立于不致之地的竞争力之一,2009年10月12-14日在河北石家庄召开的中国畜牧兽医学会2009年学术年会上。专家们从新药研发的研发流程和安全性评价、未来发展及善用寄生虫药物的开发方向等方面对我国的兽药研发提出了不同的见解．本刊特将有关内容整理并茂螭如下,希望能对兽药企业厦有关单位研发新兽药产品有所帮助和启发。     

Glycoalkaloid development during greening of fresh market potatoes (Solanum tuberosum L.)

Chlorophyll and glycoalkaloid synthesis in potato (Solanum tuberosum L.) tubers occur in direct response to light. The two processes are concurrent, but independent. Color photographic indices to subjectively grade fresh market potatoes for the extent of greening were developed under lighting conditions consistent with those of retail markets. Total glycoalkaloid (TGA) and chlorophyll accumulation for four cultivars were determined over the respective greening scales, thus calibrating the scales for TGA content. On average, TGA concentrations in complete longitudinal sections of tubers (flesh samples) were highest in Dark Red Norland followed by Russet Norkotah, Yukon Gold, and White Rose. TGA concentrations of flesh samples of White Rose and Yukon Gold tubers were somewhat variable and did not increase in direct proportion to greening level and chlorophyll content, particularly at higher levels of greening. TGA concentrations in Dark Red Norland and Russet Norkotah tubers were highly correlated (P < or = 0.001) with greening level and chlorophyll concentrations. When averaged over greening levels, skin samples contained 3.4- to 6.8-fold higher concentrations of TGAs than flesh samples, depending on the cultivar. The TGA concentration in periderm samples ranged from 37 to 160 mg/100 g of dry wt. Regardless of greening level, concentrations of TGAs in the flesh samples (including attached periderm) remained within limits presumed safe for human consumption. Discrimination of greened tubers on the basis of perceived glycoalkaloid toxicity is likely unfounded for the cultivars and greening levels studied.     

The relationship between in vivo limb and in vitro tendon mechanics after injury: a potential novel clinical tool for monitoring tendon repair

Reasons for performing the study: Highly prevalent superficial digital flexor tendon (SDFT) injury results in compromised tendon function through fibrosis and high frequency of re‐injury due to altered biomechanical function. This study investigated the consequences of SDF tendinopathy on limb mechanics in relation to the mechanical properties of injured tendon. Objectives: To develop and validate a noninvasive in vivo assessment of tendon mechanics to investigate the effect of recent SDFT injury on limb stiffness index, providing an objective method to assess quality of healing. Hypotheses: Limb stiffness index would reduce as a consequence of SDFT injury and progressively increase during tendon healing and correlate with in vitro mechanical properties of the respective SDFTs. Methods: Kinematic analysis was performed at walk in 10 horses that had sustained career‐ending SDFT injury. Stiffness index was derived from limb force recorded via a series of force plates and measurement of change in metacarpophalangeal joint angle using 3D motion analysis software. Horses were subjected to euthanasia 7 months after injury, the SDFTs removed and subjected to nondestructive in vitro mechanical testing. Results: Limb stiffness index was reduced following SDFT injury in comparison with the contralateral limb and increased during the convalescent period, approximating that of the contralateral limb by 7 months post injury. There was a significant positive correlation between in vivo limb stiffness index and in vitro SDFT stiffness. Clinical relevance: The ability to assess and monitor SDFT mechanical competence through limb stiffness measurement techniques in horses recovering from SDFT injury and the possibility of corroborating this with functional tendon healing may permit a more objective and accurate assessment of optimal tendon repair in the horse. This technique may be a useful method for assessing the efficacy of treatment regimens for tendinopathy and could be utilised to predict time to safe return to performance or re‐injury.     

Post harvest physiconutritional changes in Kagzi limes (Citrus aurantifolia Swingle) treated with selected oil emulsions and diphenyl

Influence of oil emulsions and diphenyl on post-harvest physico nutritionalchanges in Kagzi limes (Citrus aurantifolia) was studied. During twelvedays of storage, physiological loss in weight (PLW) and rotting were at a minimum in fruits treated with Neem (Azadirachta indica A. Juss.) oilplus diphenyl; juice content was at a maximum in mustard oil + diphenyltreated fruits. With the advancement of storage period, total soluble solidswere increased while ascorbic acid and acidity of fruits decreased. Mustardoil plus diphenyl supported maximum ascorbic acid (25.60 mg/100 ml juice) andminimum total soluble solids (9.03%).     

Dissipation of acephate, chlorpyrifos, cypermethrin and their metabolites in a humid-tropical vegetable production system

BACKGROUND: High amounts of insecticides are often used in intensive tropical vegetable production systems. Their persistence and residues in vegetables and soils need to be studied to ensure food safety and environmental stability. The dissipation of acephate, chlorpyrifos, cypermethrin and their metabolites was studied in green mustard [Brassica juncea (L.) Coss.] and soils. Two treatments, Impact 75 (acephate) and Agent 505 (cypermethrin plus chlorpyrifos), were applied 4 times at weekly intervals. RESULTS: Dissipation of acephate, chlorpyrifos and cypermethrin in green mustard and topsoils followed first‐order kinetics, with half‐lives of between 1.1 and 3.1 days in green mustard and between 1.4 and 9.4 days in topsoils (26 °C). Higher vapour pressure of insecticides and higher rainfall appeared to stimulate dissipation from the vegetable, with least effect of rainfall on chlorpyrifos. Dissipation rates in the vegetable were faster or similar (cypermethrin) to rates observed for temperate areas. Preharvest intervals of 13, 4 and 3 days were required for acephate, chlorpyrifos, cypermethrin and their metabolites to comply with the tolerance levels. The pesticide dissipation rates in soils varied by less than a factor of 3 between sites. The metabolites methamidophos and TCP derived from acephate and chlorpyrifos amounted to less than 10 and 25% by mass of the parent compounds in soils. Vegetable shading possibly retarded pesticide degradation in soil. CONCLUSION: The dissipation of pesticides and their metabolites in the vegetable was rapid and faster than the dissipation in temperate climates. The degradation rates of pesticides in the soil were equal to or slightly faster than the degradation rates in temperate soils. Copyright © 2008 Society of Chemical Industry     

不同非洲猪瘟病毒株j5R基因及其编码蛋白的比较

根据非洲猪瘟病毒ＭａｌａｗｉＬＩＬ２０／１株ｊ５Ｒ阅读框Ｃ端抗原决定簇序列制备的合成肽能被不同毒株感染康复猪的免疫血清识别。多聚酶链反应研究表明,９个不同毒株的ｊ５Ｒ基因长度略有差异;蛋白转印杂交试验证明,这种基因长度的差异导致相应蛋白多肽的长度多样性。这些结果进一步证明,长度多样性是非洲猪瘟病毒基因及其编码蛋白较为普遍的特点。     

肌肉注射盐酸头孢噻呋混悬注射液对猪安全性试验

头孢噻呋(ceftiofur)是第一个畜禽专用的第3代头孢菌素类抗生素,具有抗菌谱广、抗菌活性强、对胃酸和β-内酰胺酶较稳定、过敏反应少、毒性小、在动物体内残留低的特点[1].国内外已批准的制剂有注射用头孢噻呋钠和盐酸头孢噻呋注射液,用于肉牛、奶牛、马、羊、猪呼吸道病和1日龄鸡细菌性感染的防治[2].