Biovailability of ivermectin administered orally to dogs

The bioavailability of three formulations of ivermectin was determined following oral administration to dogs. The average peak plasma level (C _max) of ivermectin administered in the standard tablet formulation at 6 and 100 µg/kg of body weight was 2.97 and 44.31 ng/g, respectively. This suggest dose-dependent pharmacokinetics.C _max and total ivermectin bioavailability, as assessed from the area under the plasma curve (AUC), were similar between two tablet formulations of ivermectin administered at 100 µg/kg. Furthermore,C _max was similar following administration of radiolabelled ivermectin at 6 µg/kg in either a beef-based chewable formulation or in the standard tablet formulation.     

植物提取物超微粉体制备技术研究进展

植物提取物大都是脂溶性成分,因其水溶性差、生物利用度低,故其在临床上的推广应用受到了一定程度的限制。文章综述了有关能增强植物提取物水溶性的超临界流体技术、高压均质技术、液相可控沉淀技术、喷雾干燥技术、乳化溶剂扩散技术、机械研磨技术等超微粉体制备技术的研究进展。     

Sulfadiazine pharmacokinetics in grass carp (Ctenopharyngodon idellus) receiving oral and intravenous administrations

This study aimed to examine the bioavailability (BA) and pharmacokinetic (PK) characteristics of sulfadiazine (SDZ) in grass carp (Ctenopharyngodon idellus) after oral and intravenous administrations. Blood samples were collected at predetermined time points of 0.083, 0.17, 0.5, 1, 2, 4, 8, 16, 24, 48, 72, and 96 hr (n = 6). The samples were extracted and purified by organic reagents and determined by the ultra‐performance liquid chromatography. The software named 3P97 was used to calculate relevant PK parameters. The results demonstrated that the concentration–time profile of SDZ was best described by a one‐compartmental open model with first‐order absorption after a single oral dose. The main PK parameters of the absorption rate constant (K_α), the absorption half‐life (t_{1/2 Kα}), the elimination rate constant (K_e), the elimination half‐life (t_1/2Ke), and the area under concentration–time profile (AUC_0‐∞) were 0.3 1/h, 2.29 hr, 0.039 1/h, 17.64 hr, and 855.78 mg.h/L, respectively. Following intravenous administration, the concentration–time curve fitted to a two‐compartmental open model without absorption. The primary PK parameters of the distribution rate constant (α), the elimination rate constant (β), the distribution half‐life (t_1/2α), the elimination half‐life (t_1/2β), the apparent distribution volume (V_SS), the total clearance (CL), and AUC_0‐∞ were 9.62 1/hr, 0.039 1/hr, 0.072 hr, 17.71 hr, 0.33 L/kg, 0.013 L h^?1 kg^?1, and 386.23 mg.h/L, respectively. Finally, the BA was calculated to be 22.16%. Overall, this study will provide some fundamental information on PK properties in the development of a new formulation SDZ in the future and is partially beneficial for the appropriate usage of SDZ in aquaculture.     

基于斜率比法评定断奶仔猪对不同铜源的相对生物学利用率

本试验旨在研究不同铜源（硫酸铜、碱式氯化铜和柠檬酸铜）和铜添加水平（20和30 mg/kg）对断奶仔猪生长性能、血清铜含量与含铜酶活性以及组织铜含量的影响,探讨断奶仔猪对不同铜源的相对生物学利用率。试验采用3×2双因子随机区组设计,选取平均体重为（8.98±0.48） kg的杜×长×大三元杂交断奶仔猪112头,随机分为7组,每组4个重复,每个重复4头猪。对照组饲喂玉米-豆粕型基础饲粮（铜含量为7.80 mg/kg）,各试验组分别在基础饲粮中添加20或30 mg/kg硫酸铜、碱式氯化铜或柠檬酸铜（均以铜含量计）。试验预试期3 d,正试期28 d。结果表明：1）试验组与对照组断奶仔猪平均日增重、平均日采食量和料重比均无显著差异（P>0.05）。2）饲粮铜源和铜添加水平对断奶仔猪血清铜含量具有显著影响（P<0.05）,但对血清铜蓝蛋白和铜锌超氧化物歧化酶活性均无显著影响（P>0.05）。3）饲粮铜源和铜添加水平对断奶仔猪肝脏铜含量具有显著影响（P<0.05）,但对心脏、肾脏、胰脏和跖骨铜含量均无显著影响（P>0.05）。4）根据多元线性回归斜率比法计算,以血清铜...     

茶树对铝的吸收、积累特性及饮茶安全性评价

茶树是典型的富铝植物,茶又是深受人们喜爱的饮品,而铝是一种对人体健康有害的金属元素,饮茶是否会导致人体铝中毒引起人们高度关注。本文详细阐述了茶树对铝的吸收和积累特性,分析了茶汤中铝的溶出量、溶出形态及生物可给性,阐明了科学饮茶是健康安全的,并提出了合理有效的茶叶降铝措施。     

再生水灌溉对4类土壤Cd生物有效性的影响

根据国家土壤环境质量标准,选取重金属Cd含量为二级水平的4类土壤（红壤、 潮土、 土、 黑土）进行土培试验,研究再生水灌溉与小白菜生物量及Cd含量、 土壤有效态Cd含量、 pH、 微生物群落的关系,以及不同类型土壤间的差异性。结果表明, 再生水灌溉在不同类型土壤上对小白菜生物量及Cd含量、 土壤有效态Cd含量、 土壤pH和微生物数量的影响不同: 1）红壤、 潮土、 土上小白菜生物量增加显著,分别增加9.09%、 16.08%、 9.92%,黑土上增加不显著; 2）小白菜Cd含量在红壤上显著降低,由对照的0.29 mg/kg降低到0.22 mg/kg,在黑土上比对照增加了18.75%,在潮土和土上影响不大; 3）有效态Cd含量在红壤没有变化,但在潮土、 土、 黑土上增加显著; 4） 4类土壤微生物数量增加显著; 5）潮土、 土、 黑土的pH值有所降低。     

钙盐诱导下土壤锰和铁的释放及其对胡椒的生物有效性

Releases of manganese and iron ions from an albic soil (Albic-Udic Luvisol), a yellow-red soil (Hap-Udic Ferrisol) and a yellow-brown soil (Arp-Udic Luvisol) induced by calcium salt addition and their bioavailability to pepper (Capsicum frutescens L.) were studied in a pot experiment. Addition of Ca(NO₃)₂ decreased soil pH and increased both exchangeable and DTPA (diethylenetriamine pentaacetic acid)-extractable Mn and Fe in soils. Meanwhile, total Mn accumulation in the shoots of Capsicum frutescens L. on the salt-treated soils increased significantly (P< 0.01) compared with the control, suggesting that salt addition to soil induced Mn toxicity in Capsicum frutescens L. Although exchangeable and DTPA-extractable Fe increased also in the salt-treated soils, Fe uptake by the shoots of Capsicum frutescens L. decreased. The effect of added salts in soils on dry matter weight of pepper varied with the soil characteristics, showing different buffer capacities of the soils for salt toxicity in an order of yellow-brown soil > albic soil > yellow-red soil. Fe/Mn ratio in shoots of Capsicum frutescens L. decreased with increasing salt addition for all the soils, which was ascribed to the antagonistic effect of Mn on Fe accumulation. The ratio of Fe/Mn in the tissue was a better indicator of the appearance of Mn toxicity symptoms than Mn concentration alone.     

富铁水稻研究进展

本文简述了水稻品种间铁含量的差异性及其遗传控制,综述了采取提高铁绝对含量及增加其生物有效性开展富铁水稻的研究进展,包括常规育种、诱变育种、转基因技术。对富铁水稻研究中存在的问题及诱变技术在该方面的应用前景也作了探讨。     

共存阳离子（Ca、Zn、K）对土壤镉有效性的影响

采用盆栽与吸附试验,研究了镉污染赤红壤上,施用相同摩尔浓度的钙、钾与锌对小油菜生物量、镉吸收量及土壤镉吸附的影响。结果表明,低和高镉污染赤红壤上,施用锌明显增加小油菜地上部生物量,较对照分别增产21.1%和7.82%。不同阳离子（钠、钙、钾和锌离子）共存改变土壤吸附镉能力的程度不同,与钠体系相比,钙、钾和锌体系中土壤镉吸附量分别降低65.6%、72.0%和96.9%,共存离子降低土壤镉吸附量的次序为锌离子〉钾离子和钙离子,锌离子的影响最为明显。高镉污染赤红壤上,钙和钾使小油菜吸镉量分别增加5.5%和14.4%,低于低镉污染赤红壤上钙和钾使小油菜吸镉的增加量（分别为16.6%和19.6%）;锌明显降低小油菜吸镉量,高和低镉污染赤红壤上,较对照分别减少45.8%和35.0%。3种阳离子与镉共存时,对土壤镉生物有效性的影响差异取决于竞争吸附与竞争吸收的大小,其机制有待进一步探讨。