硫酸黏菌素毒性及其残留检测研究进展

对兽用硫酸黏菌素的毒副作用及其残留检测方法进行了综述,为其在畜牧兽医领域的进一步研究及应用提供参考。     

黄芩苷对黏菌素致小鼠周围神经毒性的保护作用研究

黏菌素的神经毒性是众所周知的。中药黄芩苷具有抗氧化、保护神经等作用。本试验通过设定正常组(生理盐水)、模型组(静脉注射15 mg/kg体重黏菌素)、黄芩苷高剂量组(200 mg/kg体重黄芩苷+15 mg/kg黏菌素)、黄芩苷中剂量组(100 mg/kg体重黄芩苷+15 mg/kg体重黏菌素)和黄芩苷低剂量组(50 mg/kg体重黄芩苷+15 mg/kg体重黏菌素)共5个剂量组,连续给药7 d后,进行氧化-抗氧化相关生化指标测定(MDA、SOD、CAT和GSH)、坐骨神经组织中凋亡相关因子表达(Caspase3和Bax)及碱性髓鞘蛋白(myelin basic protein,Mbp)表达的测定。结果表明,黄芩苷干预组的小鼠氧化指标明显降低,提高小鼠的抗氧化能力;Caspase3和Bax以及Mbp蛋白表达量均有降低。     

微生物浊度法测定硫酸黏菌素E含量的研究

以大肠杆菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,研究比浊法测定硫酸黏菌素及其制剂的含量。硫酸黏菌素的浓度在44.9 u/ml～93.2u/ml之间时,检测菌液接种浓度为0.3%,培养时间为2～3h,其浓度的对数值与相对应的吸光度具有良好的线性关系,相关系数：r＝0.9978。所建立的浊度法重现性较好,具有简便、精确、快速的特点,可用于硫酸黏菌素及其制剂含量的测定。     

微生物浊度法测定硫酸黏菌素及其制剂含量的研究

以大肠杆菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,研究微生物比浊法测定硫酸黏菌素及其制剂的含量.硫酸黏菌素的浓度在44.9 u/mL～93.2 u/mL之间时,检测菌液接种浓度为0.3%,培养时间为2～3 h,其浓度的对数值与相对应的吸光度具有良好的线性关系,相关系数:r＝0.997 8.所建立的微生物浊度法重现性较好,具有简便、精确、快速的特点,可用于硫酸黏菌素及其制剂含量的测定.     

硫酸黏菌素对培养分离的土壤优势细菌的影响

随着抗生素在畜禽养殖业上的广泛应用,药物残留对生态环境的潜在隐患日益突出.为了了解硫酸黏菌素在环境中残留对土壤细菌数量和耐药性的影响,本实验对硫酸黏菌素作用35 d后用纯培养法分离的土壤细菌进行了计数,并对作用70 d后的土壤优势细菌进行了抗菌药物敏感性试验.结果表明,实验组的土壤细菌总数均低于对照组,且培养分离的细菌数量与药物浓度成反比;在供试的13种抗菌药中,硫酸黏菌素敏感菌对其中的11种药物的敏感性与硫酸黏菌素耐药菌差异显著（P＜0.05）.     

硫酸多黏菌素B的脱色工艺研究

主要进行了硫酸多黏菌素B的膜脱色和活性炭脱色2种工艺的比较.结果表明,膜脱色在泵出口压力为25 kgf/cm2、料液pH值为2.5、进料温度为50℃时,其脱色率为86％;而A类活性炭的脱色条件为:料液脱色时间为50 min、进料温度为55℃、活性炭添加量为料液的2.5％时,其脱色率为75％.     

液相色谱-串联质谱法测定饲料中硫酸黏菌素

应用液质联用法检测饲料中硫酸黏菌素时,饲料中黏菌素经三氯乙酸溶液提取,同时用乙酸铅沉淀蛋白质,再用HLB固相萃取柱净化,浓缩后用超高效液相色谱-串联质谱联用仪检测,外标法定量。经试验:标准曲线浓度为10、30、100、300、1 000、3 000、10 000 ng/mL的系列黏菌素标准工作液时,线性方程为y=39.22x+119.86,相关系数为0.9945,在相应的浓度范围内,各药物定量离子峰面积与浓度呈线性相关;方法的检测限为0.01 mg/kg,定量限为:0.05mg/kg;饲料中黏菌素的平均回收率范围为70%~112%;日内变异系数范围为4%~14%,日间变异系数范围为6%~12%,方法回收率高,精密度好。     

对阿莫西林硫酸黏菌素可溶性粉含量测定中热破坏前处理法的探讨

采用高效液相色谱法和管碟法对阿莫西林硫酸黏菌素可溶性粉中黏菌素含量方法的前处理条件(95℃水浴加热1 h)进行了研究。结果表明,95℃加热破坏阿莫西林的同时,硫酸黏菌素也产生降解,效价下降约12%,提示该前处理条件有待进一步改进。本实验可为完善该质量标准提供参考。     

盐酸小檗碱和硫酸黏菌素对大肠杆菌和沙门氏菌的体外联合抗菌作用

采用微量稀释法分别测定盐酸小檗碱与硫酸黏菌素对猪、鸡源大肠杆菌和沙门氏菌的最低抑菌浓度(MIC),采用棋盘稀释法测定盐酸小檗碱与硫酸黏菌素联用对猪、鸡源的大肠杆菌和沙门氏菌的MIC,并计算联合指数(FIC)。试验结果为,对14株试验菌株的体外联合抗菌效果呈相加作用的占78.6%,呈无关作用的占21.4%,无拮抗作用。研究表明,盐酸小檗碱和硫酸黏菌素可联合应用于防治猪、鸡的大肠杆菌和沙门氏菌感染。     

阿莫西林、硫酸黏菌素混悬注射液无菌检查方法研究

目的建立阿莫西林、硫酸黏菌素混悬注射液的无菌检查方法。方法按《中国兽药典》2005年版一部附录进行试验。结果采用薄膜过滤法,每管培养基中加入不少于100万单位的青霉素酶,以1%聚山梨酯80的0.1%蛋白胨水溶液冲洗液,选择冲洗量为300mL,可消除样品对各菌株的抗菌活性。结论阿莫西林、硫酸黏菌素混悬注射液可用该方法进行无菌检查。     

The effects of canine bone marrow stromal cells on neuritogenesis from dorsal root ganglion neurons in vitro

The present in vitro study was designed to evaluate whether canine bone marrow stromal cells (BMSCs) promote neurite outgrowth from dorsal root ganglion (DRG) neurons. Bone marrow aspirates were collected from iliac crests of three young adult dogs. DRG neurons were cultured on BMSCs, fibroblasts, or laminin substrates. DRG neurons were also cultured in BMSC- or fibroblast-conditioned media. DRG neurons grown on BMSCs extended longer neurites and developed a much more elaborate conformation of branching neurites compared to those on fibroblasts or laminin. Quantitative analysis revealed that these effects were associated with the emergence of increased numbers of primary and branching neurites. The effect appears to be dependent upon cell-cell interactions rather than by elaboration of diffusible molecules. With more extensive investigations into the basic biology of canine BMSCs, their ability for promoting neurite outgrowth may be translated into a novel therapeutic strategy for dogs with a variety of neurological disorders.     

Conantokin G-induced changes in the chemical coding of dorsal root ganglion neurons supplying the porcine urinary bladder

Conantokin G (CTG), isolated from the venom of the marine cone snail Conus geographus, is an antagonist of N-methyl-d-aspartate receptors (NMDARs), the activation of which, especially those located on the central afferent terminals and dorsal horn neurons, leads to hypersensitivity and pain. Thus, CTG blocking of NMDARs, has an antinociceptive effect, particularly in the case of neurogenic pain treatment. As many urinary bladder disorders are caused by hyperactivity of sensory bladder innervation, it seems useful to estimate the influence of CTG on the plasticity of sensory neurons supplying the organ. Retrograde tracer Fast Blue (FB) was injected into the urinary bladder wall of six juvenile female pigs. Three weeks later, intramural bladder injections of CTG (120 microg per animal) were carried out in all animals. After a week, dorsal root ganglia of interest were harvested from all animals and neurochemical characterization of FB+ neurons was performed using a routine double-immunofluorescence labeling technique on 10-microm-thick cryostat sections. CTG injections led to a significant decrease in the number of FB+ neurons containing substance P (SP), pituitary adenylate cyclase activating polypeptide (PACAP), somatostatin (SOM), calbindin (CB) and nitric oxide synthase (NOS) when compared with healthy animals (20% vs. 45%, 13% vs. 26%, 1.3% vs. 3%, 1.2 vs. 4% and 0.9% vs. 6% respectively) and to an increase in the number of cells immunolabelled for galanin (GAL, 39% vs. 6.5%). These data demonstrated that CTG changed the chemical coding of bladder sensory neurons, thus indicating that CTG could eventually be used in the therapy of selected neurogenic bladder illnesses.     

Tetrodotoxin induced changes in the chemical coding of dorsal root ganglion neurons supplying the porcine urinary bladder

Tetrodotoxin (TTX) mode of action is based on a blocking of fast sodium channels in nerve cell membrane what, in turn, abolishes the propagation of the action potential along the nerve fibers. TTX is currently used in experimental therapies focused on neoplastic or neurogenic pain, however, as for now there is no data concerning the influence of TTX on dorsal root ganglion (DRG) sensory neurons function. Thus, the present study was aimed at characterization of neurochemical coding of porcine sensory bladder-projecting cells after bladder instillation with TTX. Retrograde tracer Fast Blue (FB) was injected into the urinary bladder wall of six juvenile female pigs and three weeks later bladder instillation with TTX (12 microg per animal) was carried out in all animals. A week later, DRGs of interest were harvested from all animals and the neurochemical characterization of FB+ neurons was performed using routine double-immunofluorescence labeling technique on 10-microm-thick cryostat sections. In TTX-treated animals the number of FB+ cells containing galanin (GAL), nitric oxide synthase (NOS), somatostatin (SOM) and calbindin (CB) was 2.5%, 2%, 0.25% and 0.2%, respectively and that of pituitary adenylate cyclase-activating polypeptide (PACAP)-immunoreactive (IR) cells was 43%. These data when compared with previous reports, demonstrated that TTX profoundly changed the chemical coding of porcine bladder-projecting sensory neurons thus implicating that it may be used in case of hypoactivity of afferent part of reflex arc responsible for transmission of sensory information from the urinary bladder.     

Botulinum toxin type A-induced changes in the chemical coding of dorsal root ganglion neurons supplying the porcine urinary bladder

Botulinum toxin type A (BTX) is a potent neurotoxin, which in recent years has been effectively applied in experimental treatments of many neurogenic disorders of the urinary bladder. BTX is a selective, presynaptically-acting blocking agent of acetylcholine release from nerve terminals what, in turn, leads to the cessation of somatic motor and/or parasympathetic transmission. However, application of this toxin in urological practice is still in the developmental stages and the full mechanism of its action remain elusive. Thus, the present study was aimed at investigating the neurochemical characterization of dorsal root ganglion (DRG) neurons supplying the porcine urinary bladder after BTX treatment. Retrograde tracer Fast Blue (FB) was injected into the urinary bladder wall in six juvenile female pigs and three weeks later, intramural bladder injections of BTX (100 IU per animal) were carried out in all the animals. After a week, DRG from L1 to Cql were harvested from the pigs and neurochemical characterization of FB+ neurons was performed using double- labeling immunofluorescence technique on 10-microm-thick cryostat sections. BTX injections led to a significant decrease in the number of FB+ neurons containing substance P (SP), calcitonin gene-related peptide (CGRP), calbindin (CB), somatostatin (SOM) and neuronal nitric oxide synthase (nNOS) when compared with that found in the healthy animals (19% vs. 45%, 18% vs. 36%, 0.6% vs. 3%, 0.4 vs. 4% and 0.1% vs. 6%, respectively) These data demonstrated that BTX changed the chemical coding of bladder sensory neurons, and therefore this drug should be taken into consideration when it planning experimental therapy of selected neurogenic bladder disorders.     

Fluoroscopy-guided approach to the lumbar dorsal root ganglion in dogs: cadaver study in Beagles

ObjectiveTo evaluate an approach to the canine lumbar dorsal root ganglion (DRG), a significant contributor to the pain pathway, using new methylene blue staining.Study designProspective randomized study.AnimalsA total of three Beagle dog cadavers weighing 10.4 ± 0.7 kg (mean ± standard deviation).MethodsBilateral third to fifth lumbar DRG approaches were performed in three dog cadavers positioned in sternal recumbency. The mammillary process was palpated, and a 22 gauge spinal needle was inserted through the skin 1 cm lateral to the process and directed towards the median plane at a 45° angle to the dorsal plane. The needle was advanced along the transverse plane until touching bone, or a popping sensation was detected. Under fluoroscopic guidance, the position of the needle tip was adjusted to be in the cranioventral part of the intervertebral foramen. The location of the needle was confirmed by demarcation of the nerve roots after iohexol (0.1 mL) injection. For evaluation of the DRG approach, new methylene blue (0.1 mL) was injected. Subsequently, anatomical dissection of the area was performed. The DRG staining was scored as follows: 0, no staining; 1, partial (<50%); 2, partial (≥50%); and 3, complete staining. Comparisons among the staining scores of the third to fifth DRG were assessed with the Friedman test.ResultsStaining score 3 was achieved in 14 of 18 (77.8%) sites. Staining scores 2, 1 and 0 were identified at two, one and one of the 18 sites, respectively. No significant difference was noted in the staining scores among the third to fifth DRGs (p = 0.78).Conclusions and clinical relevanceThe technique used for DRG injections achieved adequate DRG staining, supporting use of the fluoroscopy-guided approach to the canine lumbar DRG.     

阿莫西林与硫酸粘菌素联合抗菌活性的研究

近年来,我国兽医临床畜禽疾病多呈混合感染或继发感染,导致现有单一抗感染药物无法控制多种病原体混合感染的局面,因此,联合用药已成为克     

Localization, morphology, and immunohistochemistry of spinal cord and dorsal root ganglion neurons that innervate the gastrocnemius and superficial digital flexor muscles in cattle

OBJECTIVE: To determine the location, morphology, and neurochemical code of spinal cord and dorsal root ganglion neurons that innervate the gastrocnemius muscle (GM) and superficial digital flexor muscle (FDSM) in cattle. ANIMALS: 5 healthy Friesian male calves. Procedure: 2 different types of neuronalretrograde fluorescent tracers (fast blue and diamidino yellow) were injected into the GM and FDSM, respectively. The neurochemical code (substance P, calcitonin gene-related peptide, galanin, and neuronal nuclear protein) of labeled neurons was investigated by immunohistochemistry. RESULTS: Neurons innervating the GM and FDSM were located along the L6-S2 spinal cord segments and ganglionic levels. A cranial-to-caudal topographic distribution for each muscle was found, indicating that the motor nuclei of the 2 muscles are organized by a somatotopic pattern. The GM and FDSM motoneurons were immunoreactive only for calcitonin gene-related peptide, whereas the afferent neurons were immunoreactive for all of the neurochemical markers considered. CONCLUSION AND CLINICAL RELEVANCE: In our study, location and the extent of neurons that supply the GM and FDSM of cattle were characterized completely. Because the GM and FDSM are involved in spastic paresis of calves and it is thought that spastic paresis results from an excessive activity of the neuromuscular spindle reflex arc, findings in our study may be useful for further electrophysiologic and clinical studies. Knowledge of the neurochemical code of neurons that supply the GM and FDSM in healthy calves could be used to compare chemical alterations in the same neuronal population of affected calves.     

雌激素受体与M2mAchR在成年雌兔背根神经节中的共存

为检测成年雌兔背根神经节中是否存在雌激素受体(ER)与M2型乙酰胆碱受体(M2mAchR)的分布与共存,采用免疫荧光双标记染色法对ER与M2mAchR在背根神经节中的分布情况进行了研究。结果显示,在成年雌兔背根神经节中:(1) ER分布主要以神经元为主。其中,ERα主要表达于中小型神经元,而ERβ则多分布于大中型神经元。(2)相较ER而言,M2mAchR分布更为广泛,除神经元外,神经纤维等组织上也有弱阳性表达。(3)两种ER与M2mAchR均有共存现象,但共存情况存在差异,ERα/M2mAchR主要共分布于中小型细胞,ERβ/M2mAchR主要共分布于大中型神经元。结果表明,首先,雌激素具有通过影响背根神经节部分神经元的活动而实现对躯体内脏感觉活动间接调节的条件。其次,在此影响的机制中,雌激素除可以直接作用于神经元上的受体之外,还具有与共表达的M2mAchR交互作用而实现的条件。为研究雌激素影响神经系统调控活动的机制以及背根神经节的神经内分泌调节机制提供了重要的形态学依据。     

The influence of resiniferatoxin on the chemical coding of neurons in dorsal root ganglia supplying the urinary bladder in the female pig

Although resiniferatoxin (RTX) becomes more often used in experimental therapies of sensory system disorders, so far there is no data concerning the influence of RTX on the chemical coding of neurons in dorsal root ganglia (DRG) supplying the urinary bladder in the pig, an animal species considered as a reliable animal model for investigation dealing with human lower urinary tract disorders. Retrograde tracer Fast Blue (FB) was injected into the wall of the right half of the urinary bladder in six juvenile female pigs, and three weeks later, bladder instillation of RTX (500 nmol per animal) was carried out in all the animals. After a week, DRGs were harvested from all the pigs and the neurochemical characterization of FB+ neurons was performed using routine single-immunofluorescence labeling technique on 10-microm-thick cryostat sections. RTX instillation resulted in a distinct decrease in the numbers of FB+ cells containing calcitonin gene-related peptide (CGRP), nitric oxide synthase (NOS), somatostatin (SOM) and calbindin (CB) when compared with those found in the healthy animals (18% vs. 36%, 1% vs. 6%, 0.8% vs. 4% and 0.5% vs. 3%, respectively), and an increase in the number of pituitary adenylate cyclase-activating polypeptide (PACAP)- and galanin (GAL)-immunoreactive (IR) nerve cells (51% vs. 26% and 47% vs. 6.5%). The results obtained suggest that RTX could be taken into consideration when the neuroactive agents are planned to be used in experimental therapies of selected neurogenic bladder illnesses.     

硫酸黏杆菌素的体外抑菌活性测定

采用试管二倍稀释法测定了硫酸黏杆菌素对大肠杆菌和沙门氏菌的最低抑菌浓度，结果表明硫酸黏杆菌素对试验菌株有良好的生长抑制效果。