锌对雏鸭外周血T-淋巴细胞的影响

15 0只 1日龄天府肉鸭健雏随机分为 3组 ,分别喂给缺锌 (每千克日粮含 Zn 2 2 .9mg)、对照 (每千克日粮含 Zn10 0 mg)和锌中毒 (每 kg日粮含 Zn130 0 mg)日粮 7周或 4周 ,以酸性 - α-醋酸萘酯酶 (ANAE)染色法观测外周血 T-淋巴细胞的动态变化。结果锌缺乏组和锌中毒组雏鸭外周血 T-淋巴细胞的 ANAE阳性率显著低于对照组 (P<0 .0 1) ,表明锌缺乏或锌中毒可抑制 T-淋巴细胞的生成 ,降低其在外周血中的数量。本试验还对锌缺乏和锌中毒引起的外周血 T-淋巴细胞减少的机理进行了探讨     

Susceptibilities of some aquatic ferns to paddy herbicide bensulfuron methyl

Paddy herbicides have the potential to cause adverse effects on non-target plants. Susceptibilities of some aquatic ferns ( Azolla japonica Franch. et Savat., Isoetes japonica A. Braun, Marsilea quadrifolia L. and Salvinia natans All.) and duckweeds ( Lemna minor L. and Spirodela polyrhiza Schleid.) to paddy herbicide bensulfuron methyl (BSM) were evaluated with a 20 day exposure experiment using 200 cm² pots. The BSM concentrations in the surface water of monitoring pots with no plants dissipated exponentially with half lives of 3.5 and 3.9 days at application rates of 15 and 150 g ha⁻¹, respectively. The BSM concentrations in the surface water 1 day after application in the culture pots were comparable among plant species, and were lower than those in the monitoring pots. Bensulfuron methyl reduced the plant growth in all species. I . japonica showed the lowest intrinsic relative growth rate (RGR) and the lowest susceptibility with an effective dose resulting in 50% growth inhibition (ED₅₀) of 21 g ha⁻¹. Except for I . japonica , the RGR of the duckweeds was similar to the ferns, and ED₅₀ for the duckweeds was higher than the ferns. ED₅₀ for Sa . natans , A . japonica and M . quadrifolia were 1.1, 1.8 and 1.2 g ha⁻¹, respectively, which were smaller than 1/20 of the recommended field dose (51–75 g ha⁻¹) and ranged from 1/2 to 1/6 of ED₅₀ for L . minor and Sp . polyrhiza (6.5 and 3.2 g ha⁻¹, respectively). These results suggest that BSM application in paddy fields and its runoff in some localities is expected to have adverse effects on the growth of Sa . natans , A . japonica and M . quadrifolia .     

pH及阳离子浓度对柞蚕蛹蛋白溶解性的影响

对不同pH及阳离子浓度下柞蚕蛹蛋白的溶解性进行了研究。结果表明,柞蚕蛹蛋白的等电点pI为4.2~4.5。测定不同的阳离子对其溶解度的影响顺序为Zn2+>Ca2+>Mg2+>Na+,随着阳离子浓度的增加,蛹蛋白的溶解性增加,当离子浓度超过1.0 mol/L时,其溶解性则降低。     

银合欢对肉鸡临床毒性及减毒的研究

为研究银合欢对肉鸡的临床毒性和减毒作用,250只10日龄AA肉鸡随机分为五组,每组50只.在试验组的日粮中分别添加5%,10%,20%的银合欢进行试验,为期50天.通过对肉鸡生产性能,血液激素水平和粪中含羞草素含量的测定,结果显示适量添加银合欢可增加平均日增重,平均日采食量,减低饲料消耗率.银合欢的安全添加量应不超过饲料量的5%.     

铜中毒对雏鸭某些血液指标的影响

选用1日龄天府肉鸭210只,随机分为3组,分别喂以对照日粮(Cu12.16mg/kg)、铜中毒日粮(Cu850mg/kg)和铜中毒日粮(Cu1050mg/kg)。试验期7周。以血液病理学方法观察了铜中毒对雏鸭某些血液学指标的影响。结果显示铜中毒组、组雏鸭分别于2周龄和3周龄开始出现临床症状,死亡18只和5只。血液病理学变化表现为,红细胞大小不等、变形变性、坏死溶解;红细胞数量和血红蛋白含量显著降低(P<0.01),血清谷丙转氨酶、谷草转氨酶活性显著升高(P<0.05或P<0.01),血清铜蓝蛋白活性下降。结果表明,铜中毒对雏鸭的生长发育和上述血液指标影响明显。     

Effects of p.o. administered xylitol in cats

Xylitol is commonly used as sugar substitute in households. While it has numerous beneficial effects on human health, it is highly toxic to dogs. The goal of this study was to examine whether xylitol has similar deleterious effects, such as hypoglycaemia and acute hepatic failure, on cats. Our research included six healthy middle‐aged cats. Xylitol was dissolved in deionized water and administered p.o. at three doses (100, 500 and 1,000 mg/kg body weight). These dosages have been considered toxic and can cause liver failure or even death in dogs. After every xylitol administration, the basic health status and the blood glucose of cats were observed regularly. Additionally, prior to and 6, 24 and 72 hr after xylitol administration, blood samples were taken to check complete blood count, clinical biochemical parameters and enzymes such as ALT, ALKP, GGT, GLDH, bile acids, BUN, creatinine, phosphate, total protein, albumin, sodium and potassium. There were no significant changes (p > .05) in any of the haematological or biochemical parameters. Blood glucose concentrations did not show any significant alterations, except at 1,000 mg/kg dose, where a mild but significant increase was observed, but it was in physiological range. Based on our results, xylitol did not induce toxic effects on cats.     

Differential Cl−/Salt Tolerance and NaCl‐Induced Alternations of Tissue and Cellular Ion Fluxes in Glycine max,Glycine soja and their Hybrid Seedlings

The salt‐sensitive Glycine max N23674 cultivar, the salt‐born Glycine soja BB52 population, and their hybrid 4076 strain (F₅) selected for salt tolerance generation by generation were used as the experimental materials in this study. First, the effects of NaCl stress on seed germination, tissue damage, and time‐course ionic absorption and transportation were compared. When qualitatively compared with seed germination appearance in culture dishes, and tissue damages on roots or leaves of seedlings, or quantitatively compared with the relative salt injury rate, the inhibition on N23674 was all the most remarkable. After the exposure of 140 mm NaCl for 1 h, 4 h, 8 h, 12 h, 2 days and 4 days, the content of Cl^? gradually increased in the roots and leaves of seedlings of BB52, 4076 and 23674. Interestingly, the extents of the Cl^? rise in roots of the three experimental soybean materials were BB52 > 4076 > N23674, whereas those in leaves were just on the contrary. Secondly, by using the scanning ion‐selective electrode technique (SIET), fluxes of Na⁺ and Cl^? in roots and protoplasts isolated from roots and leaves were also investigated among the three experimental soybean materials. After 140 mm NaCl stress for 2, 4 and 6 days, and when compared with N23674, slighter net Cl^? influxes were observed in root tissue and protoplasts of roots and leaves of BB52 and 4076 seedlings, especially at the cellular protoplast level. The results indicate that with regard to the ionic effect of NaCl stress, Cl^? was the main determinant salt ion for salt tolerance in G. soja, G. max and their hybrid, and the difference in their Cl^?/salt tolerance is mainly attributed to the capacity of Cl^? restriction to the plant above‐ground parts such as leaves.     

汞水平对苋菜种子萌发的影响

采用不同浓度的氯化汞溶液(0.5、1.0、2.5、5.0、10.0、25.0、50.0、100.0 mg/L)对不同品种苋菜种子进行浸种处理。结果表明,Hg+对苋菜种子萌发的影响在低浓度时有促进作用,随着Hg+浓度增加,苋菜种子的根长和芽长都明显减少,当Hg+浓度达到100 mg/L时,苋菜种子见萌芽,但都有红褐色痕迹,即汞污染现象非常明显;Hg+较高浓度时,各个不同品种苋菜种子导电率相对较高,种子活力相对较低。     

Glycine max and Glycine soja are capable of cold acclimation

Soybean has been considered a cold intolerant species; based largely upon seed germination and soil emergent evaluations. This study reports a distinct acquisition of cold tolerance, in seedlings, following short acclimation periods. Diversity in cold responses was assessed in eight cultivars of Glycine max and six accessions of G. soja. All varieties of soybean significantly increased in freezing tolerance following acclimation. This study indicates soybean seedlings are indeed capable of sensing cold and acquiring cold tolerance. Germination rates after cold imbibition were negatively correlated with maturity group, but positively correlated with cold acclimation potential in G. soja. Seed fatty acid composition was varied between the species, with Glycine soja accessions containing about 2‐times more linolenic acid (18:3) than G. max. Furthermore, high levels of linoleic acid (18:2) in seeds were positively correlated with germination rates following cold imbibition in G. soja only. We suggest that domestication has not impacted the overall ability of soybean to cold acclimate at the seedling stage and that there is little variation within the domesticated species for ability to cold acclimate. Thus, this brief comparative study reduces the enthusiasm for the “wild” species as an additional source of genetic diversity for cold tolerance.     

玉米赤霉烯酮对动物繁殖性能的毒性作用及其机制

玉米赤霉烯酮（ZEA）一种由镰刀菌属产生的次级代谢物，化学结构与内源性雌激素相似，因此，ZEA可通过与雌激素竞争性结合雌激素受体，导致动物机体生殖激素代谢紊乱，诱发生殖器官形变及功能障碍，严重危害动物繁殖系统，解决ZEA污染问题己经成为当务之急。本文对ZEA的理化特性、毒性作用等进行综述，以期为有效缓解ZEA毒性及提高动物繁殖性能、促进畜牧业健康发展提供理论依据。