饲料中氟喹诺酮类药物检测方法研究

建立高效液相色谱—荧光检测法同时测定饲料中4种氟喹诺酮类药物的方法。样品经1%甲酸甲醇提取后,C18柱分离,荧光检测器检测,激发波长280 nm,发射波长450 nm,流动相为0.05 mol/L磷酸(用三乙胺调节pH2.4)-乙腈=85:15(v/v)。3种氟喹诺酮类药物(环丙沙星、恩诺沙星和沙拉沙星)在0.05~50μg/mL质量浓度范围内,达氟沙星在0.01~10μg/mL质量浓度范围内与峰面积呈良好的线性关系,相关系数均>0.999 6,方法精密度为1.81%~2.11%(迁移时间)和0.5%~0.92%(峰面积),在空白样品中进行3个质量浓度水平的添加,平均回收率在82.41%~103.17%,批内变异系数在0.33%~2.79%。结果表明:该法操作简便,快速准确,适合饲料中氟喹诺酮类药物的检测。     

高效液相色谱法测定羊奶中五种氟喹诺酮类药物残留量的研究

建立了一种可同时检测羊奶中五种氟喹诺酮类药物(环丙沙星、达氟沙星、恩诺沙星、沙拉沙星、二氟沙星)残留的高效液相色谱—荧光检测法。羊奶样品经乙腈提取,正己烷去脂肪,C18柱净化。以0.05 mol/L磷酸三乙胺溶液和乙腈溶液为流动相,流速为0.8 m L/min,激发波长280 nm,发射波长450 nm。结果表明环丙沙星、恩诺沙星、沙拉沙星、二氟沙星在10~200 ng/m L,达氟沙星在2~40 ng/m L呈良好的线性关系,R2均大于0.999。环丙沙星、恩诺沙星、沙拉沙星、二氟沙星的最低定量限为30μg/kg,达氟沙星的最低定量限为6μg/kg。环丙沙星、恩诺沙星、沙拉沙星、二氟沙星在30~200μg/kg的浓度添加水平上,达氟沙星在6~40μg/kg的浓度添加水平上其回收率均在70~100%,批内、批间的相对标准偏差小于20%。该方法简单快速、灵敏度高、重复性好,适用于羊奶中五种氟喹诺酮类药物残留检测。     

高压液相色谱-荧光检测法检测蜂王浆中喹诺酮类药物残留的方法

建立了一种高压液相色谱-荧光检测法同时检测蜂王浆中诺氟沙星、环丙沙星和恩诺沙星残留量的方法。采用10 m L p H3.0、0.2 mol/L的三氟乙酸溶液和20 m L乙腈作为提取液,提取液经浓缩、SCX固相萃取小柱净化、4 m L 0.1 mol/L的氢氧化钠溶液洗脱,15%柠檬酸调节p H值,荧光检测器(激发波长280 nm,发射波长450 nm)进行检测。该方法在2～50μg/kg范围内线性关系良好,提取回收率在59%～91%,方法的检测限为1.0 g/kg。由此可见,该方法检测限低,准确度高,可用于蜂王浆中3种喹诺酮类药物残留的检测。     

高效液相色谱法测定鸡血浆中恩诺沙星和环丙沙星含量

为了研究雏鸡血浆中恩诺沙星和环丙沙星含量及代谢规律,建立了本HPLC方法。血浆样品中的药物采用乙腈提取和净化,荧光检测器检测,激发波长278nm,发射波长450nm;流动相为0.05mol/L磷酸/三乙胺-乙腈(82:18,V/V)溶液。结果表明,血浆中恩诺沙星和环丙沙星的含量在0.05～10mg/L浓度范围内呈良好的线性关系,相关系数大于0.999。在低、中、高三个添加浓度(0.05、0.5、10mg/L)下平均回收率在87.26%～106.36%之间,日内变异系数低于8.97%,日间变异系数低于7.92%,检测限和定量限分别为0.01mg/L和0.05mg/L。本方法建立的血浆提取净化和检测条件可用于准确测定鸡血浆中恩诺沙星和环丙沙星的含量。     

鸡猪排泄物中恩诺沙星和环丙沙星含量HPLC检测方法的建立

建立了测定鸡、猪排泄物中恩诺沙星及环丙沙星含量的高效液相-荧光检测方法.将猪粪和鸡粪尿混合物样品分别用甲醇氨水溶液和醋酸甲醇溶液浸提,猪尿用固相萃取小柱富集净化,流动相为乙腈-三乙胺磷酸溶液（0.02 mol/L）,荧光激发波长280 nm,发射波长450 nm.检测结果表明,排泄物样品中恩诺沙星和环丙沙星含量的检测定量限,鸡粪尿混合物为0.010 μg/g,猪尿0.005 μg/mL,猪粪为0.020 μg/g.外标法标准曲线的线性范围鸡粪尿混合物中恩诺沙星为0.010～100.000 μg/g、环丙沙星为0.010～50.000 μg/g,猪尿和猪粪中恩诺沙星和环丙沙星的线性范围分别为0.005～0.500 μg/mL和0.020～1.000 μg/g.恩诺沙星和环丙沙星的回收率分别大于75%和88%.HPLC方法的样品前处理和检测方法简便、快捷,准确性较微生物检测法高.     

噁喹酸、氟甲喹在鱼组织中残留量的检测方法研究

用高效液相色谱法,荧光检测器,同时检测鱼组织中噁喹酸、氟甲喹的残留量。用乙酸乙脂作为提取液,匀浆、离心、浓缩。HPLC条件:荧光检测器,激发波长325nm,发射波长369nm。流动相:0.02mol/L磷酸 乙腈 四氢呋喃(69 16 15)。噁喹酸、氟甲喹标准曲线线性范围10~500ng/mL,对带皮的鱼肉组织,进行3种浓度的回收率测定,其回收率在80%~100%之间,变异系数在11%以内。噁喹酸、氟甲喹的检测灵敏度为20ng/g。     

噁喹酸、氟甲喹在鸡组织中残留量的检测方法研究

用荧光检测的高效液相色谱法同时检测鸡组织中噁喹酸、氟甲喹的残留量。用1 mol/L磷酸二氢钾溶液作为提取液,过C18固相萃取柱净化、浓缩。HPLC条件:荧光检测器,激发波长325 nm;发射波长369 nm。流动相:0.02 mol/L磷酸-乙腈-四氢呋喃(69∶16∶15)。噁喹酸、氟甲喹标准曲线线性范围在10~500 ng/mL。对不同组织的3种浓度进行回收率测定,其回收率在61%~92%之间,变异系数在15%以内。噁喹酸、氟甲喹的检测灵敏度为20 ng/g。     

氟苯尼考粉中非法添加四种喹诺酮类药物的HPLC检测方法研究

建立了高效液相色谱法检测氟苯尼考粉中非法添加氧氟沙星、诺氟沙星、环丙沙星、恩诺沙星的方法.用十八烷基键合硅胶色谱柱,以A(磷酸3.0 mL加水至1000 mL,三乙胺调pH值至3.0±0.1,加乙腈50 mL)-甲醇(88:12)为流动相,采用二极管阵列检测器,采集波长为200 ～400nm,分辨率1.2 am,记录光谱图和283 nm波长处的色谱图,流速1.0 mL/min,柱温30℃.结果显示,4种喹诺酮类药物的浓度在0.5 ～ 200 μg/mL范围内呈良好的线性关系,添加回收率在98.5％ ～100.9％之间,相对标准偏差在0.14％ ～ 0.74％之间,检测限0.5 mg/g.本方法快速、准确,可用于氟苯尼考粉中非法添加喹诺酮类药物的定性和定量检测.     

高效液相色谱法测定大黄末中大黄蒽醌的含量

建立了大黄末中大黄蒽醌含量测定的高效液相色谱方法。采用Agilent Eclipse XDB-C18色谱柱(250 mm×4.6 mm,5μm),甲醇-0.1%磷酸溶液(85∶15)为流动相,流速1.0 m L/min,荧光检测器检测,激发波长为442 nm,发射波长为514 nm。大黄酸、大黄素、大黄酚的浓度分别在0.2108-10.540 0μg/m L(r=0.999 9)、0.200 0-10.000 0μg/m L(r=0.999 6)、0.209 2-10.460 0μg/m L(r=0.999 5)范围内线性关系良好;平均回收率(n=3)分别为103.5%(RSD为3.0%)、102.3%(RSD为2.6%)、98.76%(RSD为2.9%)。结果提示,本方法准确灵敏,可用于大黄末的质量控制。     

HPLC-PDA法测定恩诺沙星注射液中非法添加乙酰甲喹和水杨酸

建立了高效液相色谱法测定恩诺沙星注射液中非法添加乙酰甲喹、水杨酸含量的方法。试验采用十八烷基硅烷键合硅胶色谱柱,以0.025 moL/L磷酸溶液-乙腈(85∶15,V/V)为流动相,流速为1.0 m L/min,二极管阵列检测器进行全扫描和232 nm波长测定。结果表明乙酰甲喹在0.5～20μg/m L范围内线性良好,R~2=1.000,平均回收率为99.62%;水杨酸在1.0～50μg/m L范围内线性良好,R~2=1.000,平均回收率为99.51%;RSD在0.07%～3.44%之间。本方法准确、可靠、重现性好,可用于恩诺沙星注射液中非法添加乙酰甲喹、水杨酸的定性和定量检测。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

Hypothalamic dopamine is required for salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relationship between hypothalamic dopamine (DA) and salsolinol (SAL) for the secretion of prolactin (PRL) in goats. SAL or thyrotropin‐releasing hormone (TRH) was intravenously injected into female goats treated with or without the D₂ DA receptor antagonist haloperidol (Hal), which crosses the blood‐brain barrier, and the PRL‐releasing response to SAL was compared with that to TRH. PRL‐releasing responses to SAL, Hal, and Hal plus SAL were also examined after a pretreatment to augment central DA using carbidopa (Carbi) and L‐dopa. The PRL‐releasing response to Hal alone was greater than that to SAL or TRH alone. The PRL‐releasing response to Hal plus SAL was similar to that of Hal alone. In contrast, the PRL‐releasing response to Hal plus TRH was greater than that to TRH or Hal alone. The treatment with Carbi plus L‐dopa inhibited SAL‐ and Hal‐induced PRL secretion. The inhibition of the PRL‐releasing response to SAL disappeared when SAL was injected with Hal. These results indicate that the mechanisms underlying the SAL‐induced PRL response differ from those of TRH, and suggest that hypothalamic DA and its synthesis is associated in part with SAL‐induced PRL secretion in goats.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Laboratory diagnosis of respiratory diseases of cattle

The authors describe the procedure of laboratory diagnosis for bovine respiratory diseases: direct diagnosis by isolation and for identification of bacteria or viruses and indirect diagnosis by serological methods. They specify the restraints and limits of this diagnosis and the significance results which are obtained and connected with knowledge of anamnestic information.     

The effect of peri-parturient anthelmintic treatment on the productivity of dairy cattle in subtropical western India

Trials with fenbendazole (Panacur, Hoechst India Ltd) were carried out on two commercial farms in subtropical western India to study the response and economics of nematode treatment in adult dairy cows. Milk yield, lactation length, time to first oestrus and worm egg output were monitored in treated and control groups. Treatment reduced the egg count considerably. Treated cows produced 142 litres more milk over 100 days (p<0.05), with extension of lactation length and advancement of time to first oestrus. The economic gain in terms of milk yield far outweighed the cost of anthelmintic used.     

An Evaluation of the Acceptability as Forage of Some Nutritive and Antinutritive Components and of the Dry Matter Degradation Profiles of Five Species of Ficus

The suitability of five species of Ficus, F. mucoso, F. thonningii, F. polita, F. religiosa and F. benjamina, for feeding ruminant livestock was studied. The nutritive and antinutritive components were determined and the acceptability of the forages to livestock was assessed using a cafeteria method in 8 adult small ruminants. Also, the degradation potential of the dry matter of the five Ficus species was investigated using 3 fistulated sheep. The crude protein (CP) content of the Ficus species varied significantly (p < 0.05), ranging from 130 to 180 g/kg DM. The content of neutral detergent fibre (NDF) also varied significantly (p < 0.05), ranging from 650 to 710 g/kg DM. The organic matter (OM) contents did not differ significantly (p > 0.05), having a mean value of 916 g/kg DM. The concentrations of tannin, saponin, phytic acid and oxalic acid were low. The acceptability of the forage was similar for four of the species but poor for F. polita. The extent of DM degradation varied significant among the Ficus species, the ranking order being F. benjamina > F. thonningii > F. mucoso > F. religiosa > F. polita.