纳米混悬制剂在兽药中的研究进展

部分兽药原料药由于水溶性较差或渗透性较低，导致生物利用度低，不能发挥良好的疗效。将药物制成纳米混悬制剂，能够减小药物粒度，改善药物溶解度，增加药物溶出度，并改变药物在生物体内的药代动力学特征，有效提高生物利用度。另外，纳米混悬制剂具备制造方法简单、条件温和等优势，满足理想的兽药开发条件。本文就纳米混悬制剂的制备方法，及其在兽药应用领域给药途径进行了综述，为纳米混悬制剂在兽药领域的研制提供参考及借鉴。     

固体分散体的研究及其应用

固体分散技术是指制备制剂时将同体药物,特别是难溶性药物高度分散在另一种固体载体中的新技术.在制剂中,我们可以通过改变剂型、处方组成和工艺等方法来改变药物的分散状态,从而达到药物速效、高效、缓释及提高生物利用度的目的.     

中药汤剂分散体系形成机理的思考

<正>药物的溶解度直接影响药物在体内的吸收和生物利用度,在中药中存在很多药理活性强但溶解性差的成分,如葛根素、喜树碱、鱼腥草素、二氢槲皮素等,需设法增加其溶解度以满足制剂生产和临床用药的需求。近年来,分子包合、固体分散体及微乳等新技术,取得了较好研究成果。但上述方法均存在需添加辅料、借助特殊工艺或设备、适用性有限、带来新的安全隐患等共性问题,制约了其在中药领域的应用[1]。比较而言,中药汤剂作为目前临床最常用的一种剂     

固体脂质纳米粒内服吸收机制及影响因素研究进展

大多数兽药由于渗透性、稳定性和溶解性差以至于无法抵御胃肠道化学和酶等不利环境的降解,不能有效突破胃肠道黏膜屏障,导致生物利用度并不理想。如何保护药物的稳定性并突破消化道黏膜屏障从而提高药物的内服吸收是药物研究者急需寻找解决方案的科学难题。固体脂质纳米粒能提高药物的稳定性并通过不同的转运方式突破胃肠道生理学屏障,从而有效提高药物的内服吸收,表现出显著的疗效,具有良好的发展前景。介绍固体脂质纳米粒的内服吸收机制和胃肠道生理学因素如胃肠道内理化环境、黏液屏障、紧密连接、上皮细胞以及上皮下结缔组织,以及纳米粒的粒径、表面修饰和电荷对其吸收效率的影响,以期为药物研究者提供有效的借鉴。     

兽用抗寄生虫药物新剂型及其新技术的研究进展

兽用抗寄生虫药物由于使用频繁,其给药技术研究一直备受重视.目前,兽用抗寄生虫药物新剂型和新技术的研究主要集中在缓释控释制剂和脂质体制剂,其次是透皮给药系统、微囊、微球、环糊精包合物、固体分散体等.但这些新剂型和新技术大多还处于研究阶段,在处方设计或制剂工艺方面都还存在一些问题,今后应加强这些新剂型的工艺和技术研究,以真正发挥这些新剂型的优点.     

兽药新剂型研究进展

目前国内开发的兽药以抗茵药物为主，抗寄生虫药其次，开发品种以仿制为主。随着各种制剂新技术的发展与应用，已逐渐由用量最大的针剂、片剂向适应现代畜牧业发展的新剂型的方向转变，现将在兽医药剂中广泛使用的各种新剂型及其应用情况简要介绍一下。     

抗菌药控缓释制剂的研究进展

抗菌药制成控缓释制剂可减少服药次数和用药剂量,有利于降低药物的毒副作用,可延长有效浓度维持时间,以便更好地发挥抗菌作用。目前上市的抗菌药控缓释制剂类型和品种日渐增多,有经化学结构改造的长效抗生素,还有非胃肠道给药的乳剂,植入式药弹,缓释片和胶囊,局部药物释放系统,DepoFoam等药物缓释系统,国内外许多医疗领域(如器官移植、五官科、呼吸科、骨科等)均有其研究和应用的报道。文章就抗菌药控缓释制剂的制剂新技术、国内外研究应用概况、在兽医临床上的应用情况以及存在的问题进行了综述。     

兽药新剂型与新技术—固体分散技术

药物都应做成一定剂型，以制剂的形式应用于预防、诊断、治疗疾病。制剂的有效性、安全性、合理性和精密性等，则反映了医药工业的生产水平，决定了用药的效果。要提高药物的疗效，降低药物的毒副作用和减少药源性疾病，对药物制剂提出了更高的要求，药物的新剂型和新技术也正发挥愈来愈大的作用。药物剂型的发展经历了５个阶段：第１代剂型是药物简单加工，供口服与外用的膏、丹、丸、散剂；第２代剂型是随着生产力的发展，给药途径的扩大和工业生产的机械化和自动化，产生了片剂、注射剂、胶囊剂、气雾剂等；第３代剂型是以药物疗效与药物…     

超微粉碎技术在中兽药方面的应用进展

<正>超微粉碎技术是近十年来发展起来的新型物料加工技术,该技术是利用各种超微粉碎设备通过一定的加工工艺流程,产品加工成为细粉末的粉碎过程。相对于传统粉碎,中药通过超微粉碎后,能够显著的增加比表面积、改善药物溶出,提高药物的生物利用度,促进机体对药物的吸收,因此在中药制剂方面,尤其是在中兽药制剂     

兽用抗菌增效剂制剂的研究进展

抗菌增效剂属于人工合成的二氨基嘧啶类药物，此类药物与抗菌药物联合使用时会以特定的机制来增强抗菌药的药物活性。近年来，由于抗生素的广泛使用甚至滥用导致细菌耐药的问题日益显现，通过加入抗菌增效剂而研制出的新制剂可以提高抗菌药在动物体内的利用率、降低药物用量、增强药物疗效、降低兽药残留及减少细菌耐药性。文章分析了近年来甲氧苄啶、二甲氧苄啶和艾地普林与各类抗生素的联合使用制备的制剂产品，发现其对疾病的治疗效果普遍优于单独使用抗生素。同时，配合中药的使用对细菌耐药的问题有显著改善，为后期抗菌增效剂的研究打开新的局面。随着对兽药制剂的研究，其不再局限于简单的剂型，通过运用新技术、新材料研制出的制剂，针对不同的给药部位和给药途径可以对病患进行更精准的治疗，减少药物达到靶部位的时间，增加患病部位的药量，此思路可为后续的研发方向提供支持和参考。文章将对抗菌药-抗菌增效剂联用制剂的研发情况进行综述。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

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.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.