Effects of three antagonists on selected pharmacodynamic effects of sublingually administered detomidine in the horse

ObjectiveTo describe the effects of alpha₂-adrenergic receptor antagonists on the pharmacodynamics of sublingual (SL) detomidine in the horse.Study designRandomized crossover design.AnimalsNine healthy adult horses with an average age of 7.6 ± 6.5 years.MethodsFour treatment groups were studied: 1) 0.04 mg kg^?1 detomidine SL; 2) 0.04 mg kg^?1 detomidine SL followed 1 hour later by 0.075 mg kg^?1 yohimbine intravenously (IV); 3) 0.04 mg kg^?1 detomidine SL followed 1 hour later by 4 mg kg^?1 tolazoline IV; and 4) 0.04 mg kg^?1 detomidine SL followed 1 hour later by 0.12 mg kg^?1 atipamezole IV. Each horse received all treatments with a minimum of 1 week between treatments. Blood samples were obtained and plasma analyzed for yohimbine, atipamezole and tolazoline concentrations by liquid chromatography-mass spectrometry. Behavioral effects, heart rate and rhythm, glucose, packed cell volume (PCV) and plasma proteins were monitored.ResultsChin-to-ground distance increased following administration of the antagonists, however, this effect was transient, with a return to pre-reversal values as early as 1 hour. Detomidine induced bradycardia and increased incidence of atrioventricular blocks were either transiently or incompletely antagonized by all antagonists. PCV and glucose concentrations increased with tolazoline administration, and atipamezole subjectively increased urination frequency but not volume.Conclusions and clinical relevanceAt the doses administered in this study, the alpha₂-adrenergic antagonistic effects of tolazoline, yohimbine and atipamezole on cardiac and behavioral effects elicited by SL administration of detomidine are transient and incomplete.     

人参根际土壤中拮抗人参病害微生物的筛选

【目的】筛选对人参主要病原菌拮抗率更高、抑菌谱更广的新菌株生防菌种资源.【方法】稀释平板法分离拮抗菌;平板对峙法筛选拮抗菌.【结果和结论】筛选出对人参单一病原菌有高拮抗活性的放线菌7株,对人参疫病、菌核病、灰霉病、黑斑病、锈腐病、立枯病、根腐病拮抗率分别为80.84%、82.46%、66.08%、71.33%、64.63%、85.53%、65.11%,其中对7大人参病害均有高拮抗活性的菌株有5株,包括1株木霉菌、4株放线菌.研究结果表明,可利用人参根际土壤中的有益菌研究其生防潜力,用于人参主要病害的防治.     

In Vitro and In Silico Characterization of G-Protein Coupled Receptor (GPCR) Targets of Phlorofucofuroeckol-A and Dieckol

Phlorotannins are polyphenolic compounds in marine alga, especially the brown algae. Among numerous phlorotannins, dieckol and phlorofucofuroeckol-A (PFF-A) are the major ones and despite a wider biological activity profile, knowledge of the G protein-coupled receptor (GPCR) targets of these phlorotannins is lacking. This study explores prime GPCR targets of the two phlorotannins. In silico proteocheminformatics modeling predicted twenty major protein targets and in vitro functional assays showed a good agonist effect at the α2C adrenergic receptor (α_2CAR) and an antagonist effect at the adenosine 2A receptor (A_2AR), δ-opioid receptor (δ-OPR), glucagon-like peptide-1 receptor (GLP-1R), and 5-hydroxytryptamine 1A receptor (5-TH_1AR) of both phlorotannins. Besides, dieckol showed an antagonist effect at the vasopressin 1A receptor (V_1AR) and PFF-A showed a promising agonist effect at the cannabinoid 1 receptor and an antagonist effect at V_1AR. In silico molecular docking simulation enabled us to investigate and identify distinct binding features of these phlorotannins to the target proteins. The docking results suggested that dieckol and PFF-A bind to the crystal structures of the proteins with good affinity involving key interacting amino acid residues comparable to reference ligands. Overall, the present study suggests α_2CAR, A_2AR, δ-OPR, GLP-1R, 5-TH_1AR, CB₁R, and V_1AR as prime receptor targets of dieckol and PFF-A.     

Xylazine-induced sedation in axis deer (Axis axis) and its reversal by atipamezole

Eight free-ranging axis deer (Axis axis) were captured in drive nets and injected with xylazine (3.4±0.1 mg/kg; mean ±SEM) intramuscularly using a hand-held syringe. Xylazine induced complete immobilization and sedation in three animals, heavy sedation in three, and moderate sedation in two. The mean induction time was 10.4±1.0 min. The mean rectal temperature, heart and respiratory rates of immobilized animals were 39.2±0.4°C, 75.5±6.5 beats/min and 62.1±4.2 breaths/min, respectively.All the animals were given atipamezole intravenously for reversal. The mean time from injection of xylazine to administration of atipamezole was 37.8±4.6 min. A dose ratio (w/w) for xylazine:atipamezole-HCl of 10:1 was used. The mean time from injection of atipamezole to mobility was 2.41±0.58 min.Atipamezole given intravenously effectively antagonized xylazine-induced sedation in axis deer. Only one animal showed signs of overalertness after reversal and no cases of resedation were observed.Abbreviations i.m. intramuscular(ly) - i.v. intravenous(ly) - SEM standard error of the mean     

不同种类生物有机肥对烤烟青枯病及烟叶生长的影响

为探索不同种类生物有机肥对烟叶青枯病的防治效果,以期为生态、优质、安全烤烟生产的田间管理提供科学参考。通过田间小区试验,对7种不同有机肥配施拮抗菌对烤烟生长、产量及青枯病的影响效果做了分析比较。结果表明:有机肥配施拮抗菌促进了烟叶前期生长,上等烟比例提高了12.80~33.59个百分点,但产量降低了2.91%~38.18%;7个生物有机肥处理均减缓了烟叶生长前期的青枯病发病情况,进入成熟采烤期后,只有处理4[3750 kg/hm2有机肥(20%菜枯+20%碳化谷壳+60%烟草秸秆粉碎物)]、处理3[3750 kg/hm2有机肥(40%茶枯+60%烟草秸秆粉碎物)]和处理5[3750 kg/hm2有机肥(20%茶枯+20%碳化谷壳+60%烟草秸秆粉碎物)]的病情指数低于对照,防治效果分别为54.22%、43.37%和31.32%。采用处理4、处理3和处理5时,应根据烟叶田间生长情况,适当进行追肥,以达到既能提高烟叶的产量、上等烟比例,又能防治烟叶青枯病的效果。     

Exposure to biological fungicides,environmental microorganisms and oils in forestry harvesting

New chemicals have been introduced into forestry harvesting during the past decade. In field experiments five harvesters and their operators were used to study exposure to biological fungicides, biodegradable oils and log colour-coding agents. Respiratory exposure to the biological fungicide Phlebiopsis gigantea, other basidiomycetes, environmental microorganisms and endotoxins was assessed using samples taken from the workers’ breathing zone. Exposure to biological fungicide was also estimated by antibody determinations from serum samples. Dermal exposure to biodegradable oils and biological fungicides was studied using a fluorescent tracer method and digital photography. Dermal exposure to log colour-coding agents was observed visually. The field survey indicated that respiratory and dermal exposure to biological fungicides, log colour-coding agents and hydraulic and chainsaw oils was insignificant during normal harvester operations. Skin contamination may occur during maintenance work such as the sharpening of chains or the handling of hydraulic hoses.     

苏醒灵4号对兔心血管与呼吸系统的影响

苏醒灵４号是新型的动物麻醉拮抗剂。利用动脉插管技术探讨了该药对清醒兔和眠乃宁麻醉兔心血管和呼吸系统的影响，结果表明，苏醒灵４号对清醒兔心血管和呼吸系统无明显的影响，但能迅速拮抗眠乃宁对兔心血管和呼吸系统的抑制作用，表现为给药后１ｍｉｎＨＲ、ＳＰ、ＤＰ、ＭＡＰ和ＲＲ明显回升，３ｍｉｎ时ＳＰ、ＤＰ、ＭＡＰ和ＲＲ值达正常水平（Ｐ〉０．０５），而ＨＲ在３０ｍｉｎ时恢复至正常水平。眠乃宁对心电有明显的影响，Ｑ－Ｔ、Ｐ－Ｒ和ＱＲＳ间隙延长，给予苏醒灵４号后ｍｉｎ时开始回升，９０ｍｉｎ恢复至正常水平。     

苏醒灵4号的神经药理作用研究

苏醒灵4 号是一种新的复方拮抗剂。本研究旨在探讨其神经药理作用特点。苏醒灵4 号对小鼠自发活动无明显影响,但能拮抗二甲苯胺噻唑对小鼠自发活动的抑制作用;苏醒灵4 号拮抗眠乃宁对小鼠和大鼠的麻醉作用,其作用强度优于同等剂量的苯恶唑;该药对戊巴比妥钠和氯胺酮也有一定的拮抗作用。此外,该药对中枢兴奋剂印防己毒素有微弱的加强作用。总之,苏醒灵4 号本身无明显的药理活性,但能拮抗麻醉剂的中枢抑制作用。     

西南桦苗木猝倒病生防菌的筛选及鉴定研究

采用组织分离法和稀释平板法对西南桦猝倒病发生区健康苗木组织、根际土壤及咖啡壳堆肥化基质进行菌种分离和分子鉴定。将分离获得的17株菌株与西南桦苗木猝倒病病原菌尖孢镰刀菌和腐皮镰刀菌进行平板对峙实验,筛选病原拮抗菌。结果表明,筛选出的真菌5#、7#及细菌BJ、JCl对西南桦苗木猝倒病原菌尖孢镰刀菌和腐皮镰刀菌具有较强抑制效果。其中真菌5#和7#的抑菌率分别为91．30％和90．12％;细菌BJ和JCl抑菌带较宽,对峙4天分别达0．4cm和0．5cm,抑菌率分别为80．4％和78．6％,且BJ抑菌效果更好;真菌与细菌比较,拈抗真菌5#和7#比拮抗细菌BJ和JCl抑制热区西南桦苗木猝倒病菌效果更好。通过对峙实验筛选出的5#、7#、BJ和JCl拮抗菌,对热区防治苗木猝倒病及生防制剂的开发应用具有参考价值。