硫酸头孢喹肟在安格斯牛体内药物代谢动力学研究

为了探究硫酸头孢喹肟在安格斯牛体内的药物代谢动力学，对安格斯牛以2 mg/kg剂量分别进行静脉、肌肉、皮下注射后，于不同时间点颈静脉采血，应用HPLC测定血液中硫酸头孢喹肟的药物浓度，计算药动学参数。静脉、肌肉、皮下注射的消除半衰期（T1/2β）分别为（2.05±0.49）h、（2.17±0.51）h、（2.37±0.47）h，达峰时间（Tmax）分别为（0.75±0.25）h、（0.87±0.25）h、（1±0.37）h，达峰浓度（Cmax）分别为（7.31±1.98）μg/mL、（5.34±1.21）μg/mL、（5.16±1.29）μg/mL，药时曲线下面积（AUC）分别为（24.72±5.31）μg.h/mL、（19.97±3.11）μg.h/mL、（20.51±4.87）μg.h/mL，平均留置时间（MRT）分别为（2.83±0.61）h、（3.02±0.71）h、（3.26±0.89）h，清除率（CL）分别为（0.07±0.02）L/h.kg、（0.09±0.03）L/h.kg、（0.09±0.04）L/h.kg，表观分布容积（Vd）分别为（0.23±0.06）L/kg、（0.31±0.08）L/kg、（0.32±0.09）L/kg。肌肉、皮下注射的绝对生物利用度（F）分别为80.78%、82.96%。表明硫酸头孢喹肟在安格斯牛体内吸收快、消除慢，肌肉注射以及皮下注射的绝对利用度高。     

苏打碱土快速改良与草坪草种植同步的研究

针对苏打碱土区草坪建植困难，本文利用重度碱化苏打碱土加入硫酸钙、疏水材料(秸秆、石灰、沙子)和有机肥，研究实验室条件下种草生长与碱土改良同步进行的效果，为碱土地区草坪生产提供理论依据。在碱土中加入硫酸钙和疏水材料(秸秆、石灰、沙子)并混施有机肥后，播种矮生百慕大(Cynodon dactylon)、高羊茅(Festuca elata Keng ex E. Alexeev)和早熟禾(Poa annua Linn)混合种子，并用大量水淋洗，实现改良与生长同步。结果表明：经28 d生草后碱土pH值、电导率、交换性钠大幅降低，土壤微团聚体等方面均有所改变。碱土添加硫酸钙可使pH值最多下降2.18个单位，交换性钠及碱化度下降超过90%，土壤饱和导水率增加，结构明显改善，可满足草坪草的生长条件。硫酸钙改良重碱土对草坪草生长促进作用明显，加有机肥对生草促进作用不显著。本研究结果为利用苏打碱土种植草坪草提供了科学依据。     

Identification of blaIMI-mediated carbapenem-resistant Enterobacter from a duck farm in China

Carbapenem- and colistin-resistant Enterobacter has been a clinical and therapy problem in recent years. Here, we report the carbapenem- and colistin-resistant Enterobacter harboring bla_IMI isolated from intestinal samples and the environment of a duck farm in China. Four bla_IMI-positive Enterobacter isolates were resistant to carbapenem and colistin. Three bla_IMI subtypes were detected in different molecular categories of Enterobacter. The detection of the various IMI producers highlights the diversity of carbapenemases in a duck farm. Whole-genome sequencing demonstrated the bla_IMI genes were present in chromosomes or plasmids in these strains. The conjugation experiment demonstrated the ability of bla_IMI-carrying plasmid to transmit horizontally. The molecular evolution characteristics were examined through comparative genetic analysis. The study demonstrated the presence of chromosomal and plasmid bla_IMI and the bla_IMI-carrying plasmid exhibits a horizontal transmission between Enterobacter and Escherichia coli C600. The similar genetic content was discovered between two bla_IMI-16-positive Enterobacter asburiae. In addition, a bla_IMI-16-carrying plasmid is an IncFII(Yp) plasmid, and a substantial amount of mobile genetic elements were identified around bla_IMI-16. The IS-like elements and IncFII(Yp) plasmid are significant in the propagation of bla_IMI. Our study provides evidence for the transmission of diverse bla_IMI genes in China and supplies additional reference data for bla_IMI-positive antimicrobial-resistant Enterobacter. Routine surveys of bla_IMI-positive Enterobacter from animal-raising environments must be given more focus.     

Tolerance and safety evaluation of sodium sulfate:A subchronic study in laying hens

Sodium sulfate (Na₂SO₄) is a readily available chlorine-free source of sodium, which could be used to reduce sodium chloride to maintain the ratio between chlorine and sodium in poultry diets. Dietary supplementation with excessive levels of Na₂SO₄ might be detrimental to bird''s health and performance. A subchronic study was carried out to investigate the potential adverse effects of an accidental oversupply of Na₂SO₄ in the diets of laying hens. Four hundred and fifty 21-week-old Hy-Line White layers were randomly assigned to 5 treatments with 6 replicates. The birds were fed diets supplemented with 0 (control), 0.3%, 0.6%, 1.5%, and 3.0% Na₂SO₄ for 8 weeks. Laying performance, egg quality parameters, clinical blood parameters, histopathology, intestinal barrier functions, and intestinal microflora composition were measured. No clinical signs of intoxication or mortality were observed during the experimental period. The results of this study showed that the optimal levels of Na₂SO₄ (0.3% to 0.6%) significantly improved the laying rates, average daily egg mass, and eggshell quality of hens compared to the control (P < 0.05). However, 3.0% Na₂SO₄ produced negative effects on laying performance, eggshell quality, blood biochemistry, and particularly on liver and kidney pathology, and intestinal morphology and barrier functions compared with the controls. Although minor changes were observed in clinical blood parameters of hens receiving 1.5% Na₂SO₄, these were not considered to be of toxicological significance due to the absence of any organ pathological changes in hens. In conclusion, our results indicated that a Na₂SO₄ concentration of 1.5% was non-deleterious to laying hens after a daily administration for 56 d, namely that dietary supplementation of up to 5 times the maximum recommended dose is safely tolerated by laying hens.     

硫酸软骨素的开发及生产工艺控制

介绍了硫酸软骨素的临床应用，如对听觉障碍、肝肾疾患、心血管疾病、眼病、肿瘤等具有治疗抑制作用，文中对其再开发及达标生产工艺，如方法选择１、温控操作、成品纯化等作了讨论。