The effects of enrofloxacin on canine tendon cells and chondrocytes proliferation <Emphasis Type="Italic">in vitro</Emphasis>

Enrofloxacin, a fluoroquinolone antibiotic has been used widely in humans and domestic animals, including dogs, because of its broad-spectrum activity and relative safety. The side effects of fluoroquinolone, induced tendinopathy, tendonitis, spontaneous tendon rupture and cartilage damage, remain incompletely understood. In the present study, we investigated the in vitro effects of enrofloxacin on cell proliferation and induction of apoptosis in canine Achilles tendon cells and chondrocytes. Cell growth and proliferation after treating with enrofloxacin for 2–6 days was quantified by a colorimetric 2,3-bis{2-methoxy-4-nitro-5-sulfophenyl}-2H-tetrazolium-5-carboxyanilide inner salt (XTT) assay. The results showed that enrofloxacin could inhibit the proliferation of canine tendon cells and chondrocytes at increasing concentrations (10–200 μg/ml). The inhibition of proliferation of canine tendon cells and chondrocytes after exposure to enrofloxacin were associated with induction of apoptosis, as evidenced by the typical nuclear apoptotic condensed nuclei found using Hoechst 33258 staining. It was demonstrated that canine tendon cells and chondrocytes treated with 200 μg/ml enrofloxacin for 4 days exhibited apoptotic features and fragmentation of DNA. Enrofloxacin also increased the apoptosis of canine tendon cells and chondrocytes in a dose and time-dependent manner. The results indicate that enrofloxacin inhibits cell proliferation, induces apoptosis and DNA fragmentation, which might explain enrofloxacin-induced tendinopathy and cartilage damage.     

Comparative analysis of survivin expression in untreated and relapsed canine lymphoma

BACKGROUND: Survivin, a member of the inhibitor of apoptosis protein family, has a dual role in tumor cell proliferative and antiapoptotic pathways. Survivin expression has been shown to be a negative prognostic factor in several cancers of humans, including B-cell non-Hodgkin's lymphoma. HYPOTHESES: High survivin expression will be a negative prognostic factor in dogs with lymphoma (LSA) treated with chemotherapy. In addition, survivin expression will be upregulated in relapsed canine LSA when compared with patient-matched, pretreatment biopsies. ANIMALS: Thirty-one client-owned dogs with stage IIIa or IVa LSA. METHODS: Retrospective evaluation of survivin immunoreactivity was performed on pretreatment lymph node biopsies and patient-matched samples obtained from dogs at relapse after being treated with an abbreviated CHOP-based protocol. RESULTS: In this population of dogs presenting with stage IIIa or IVa B-cell LSA, those dogs that had high survivin immunoreactivity scores had a significantly (P < .01, hazard ratio = 0.30) shorter median disease-free interval than did dogs with low survivin immunoreactivity scores (171 days versus 321 days, respectively). Survivin immunoreactivity was not significantly different in relapsed canine LSA when compared with patient-matched, pretreatment biopsies. CONCLUSIONS AND CLINICAL IMPORTANCE: Survivin expression is a negative prognostic factor that can predict early treatment failure of dogs that present with stage IIIa or IVa, B-cell LSA when treated with a CHOP-based protocol.     

兔卵母细胞孤雌激活方法的研究

对兔卵母细胞的孤雌激活方法进行探讨,为兔的体细胞核移植奠定良好的技术平台。体外成熟培养20～22h的兔卵母细胞随机分组,分别进行以下试验：采用不同脉冲电压、脉冲次数和脉冲时间,电激活兔卵母细胞,摸索最佳电激活参数;比较不同的激活方法处理免卵母细胞的效果,Ⅰ：Ion5min＋6-DMAP3h,Ⅱ：Ion5min＋CHX3h,Ⅲ：Ion5min＋6-DMAP联合CHX3h,Ⅳ：电激1次联合6-DMAP＋CHX3h;优化6-DMAP与CHX作用时间。结果显示：当电激参数为：电压40V／mm,脉冲时间20μs和脉冲次数3次时,兔孤雌胚的分裂率和囊胚率最高,可达80．64％和14．51％;采用第Ⅳ种方法激活兔的卵母细胞,胚胎的分裂率和囊胚率（80．64％,13．71％）均显著高于Ⅰ组（66．67％,8．6％）和Ⅱ组（43．21％,1．24%,P〈0．05）,略高于第Ⅲ组（77．59％,12．07％）;当兔孤雌胚分别在含6-DMAP和CHX的CM中培养1。h和3h时,1h处理组在分裂率（80．68％vs77．59％）和囊胚率（15．91％vs12．07％）上都略高于3h处理组。结果表明：兔卵母细胞经Ion处理5min,或先电激1次（参数为电压40V／mm,脉冲时间20μs,脉冲3次）,再用2mmol／L6-DMAP＋5mg／LCHX处理1～3h,均可获得较好的激活效果,有利于兔孤雌胚的发育。     

4G移动通信关键技术浅析

本文对4G移动通信技术的发展实现了展望,对可能采用的关键性技术进行了分析.     

Tyrosine‐derived 4‐hydroxyphenylpyruvate reacts with ketone test fields of 3 commercially available urine dipsticks

Background: The enzyme 4‐hydroxyphenylpyruvate dioxygenase (HPPD) is key in tyrosine catabolism. Inhibition of HPPD results in tyrosinemia and increased urinary excretion of 3 phenylketones: 4‐hydroxyphenylpyruvate (HPPA), 4‐hydroxyphenyllactate (HPLA), and 4‐hydroxyphenylacetate (HPAA). A previous study involving administration of a novel HPPD inhibitor to dogs resulted in detection of ketonuria in treated animals using urine dipsticks read by reflectance photometry. Dipstick‐positive results were suspected to be false because high concentrations of urinary phenylketones have been reported to react with ketone test fields of urine dipsticks, but visual confirmation was not performed. Objective: The purpose of this study was to determine which of the 4‐hydroxyphenolic acids produced by HPPD inhibition react with ketone test fields of 3 commercially available urine dipsticks. Methods: Canine urine samples were prepared with HPPA, HPLA, HPAA, and lithium acetoacetate (positive control) at 6 concentrations. Unmodified urine samples were used as negative controls. All samples were tested for ketones using Combur 10 Test M dipsticks read by a Miditron dipstick analyzer. Urinalysis was also performed by visually inspecting ketone test fields on the Combur 10 Test M, Multistix 10 SG, and Aution 10 EA dipsticks. Results: Urine samples containing HPPA were positive for ketones with Combur 10 Test M dipsticks read by the Miditron analyzer and produced a red–brown color change in ketone test fields of all 3 dipsticks. Urine samples containing HPLA and HPAA were negative by all methods. Conclusion: The phenylketone HPPA reacts with ketone test fields of 3 commercially available urine dipsticks, producing a red–brown color change that may be misinterpreted as positive for ketones by reflectance photometry.     

镰刀菌毒素对断奶仔猪脾脏抗氧化能力和白细胞介素-1β、白细胞介素-6分布和表达的影响

本试验旨在研究自然霉变饲粮中镰刀菌毒素对断奶仔猪脾脏抗氧化能力和白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)分布和表达的影响。选择35日龄平均体重为(8.45±0.94)kg的健康三元杂交(杜×长×大)断奶仔猪母猪40头,随机分为2组,每组20头。对照组饲喂基础饲粮,镰刀菌毒素组饲喂含镰刀菌毒素[玉米赤霉烯酮(ZEN)0.90 mg/kg;呕吐毒素(DON)1.43mg/kg,烟曲霉毒素(FUM)5.85 mg/kg]的试验饲粮。预试期7d,正试期35d。结果表明:1)与对照组相比,镰刀菌毒素显著降低了断奶仔猪血清和脾脏谷胱甘肽过氧化物酶(GSH-Px)和总超氧化物歧化酶(T-SOD)活性(P0.05),显著升高了丙二醛(MDA)含量(P0.05)。2)镰刀菌毒素使断奶仔猪脾脏白髓区明显变小,红髓区扩张且出现近圆形小空洞,动脉周围淋巴鞘中淋巴细胞数量较少。3)镰刀菌毒素导致断奶仔猪脾脏IL-1β和IL-6阳性细胞主要集中于白髓边缘,且靠近血窦的地方阳性点更多。4)与对照组相比,镰刀菌毒素显著升高了断奶仔猪脾脏IL-1β和IL-6mRNA相对表达量(P0.05)。由此可见,饲粮中镰刀菌毒素显著影响断奶仔猪血清和脾脏抗氧化能力,并通过改变脾脏IL-1β和IL-6的分布和表达,降低脾脏的免疫功能。     

Analyses of monoclonal antibodies reacting with porcine wCD6: Results from the Second International Swine CD workshop

Among the 57 monoclonal antibodies analyzed within the T-cell group of the Second International Swine CD Workshop, one mAb fell within cluster T14a that included the CD6 standard a38b2 (No. 175). The new mAb MIL8 (No. 082) and a38b2 both precipitated from activated T-cells a 150 kDa monomeric protein. Staining patterns on the various cell types were similar. There was no inhibition of binding of either mAb to peripheral blood T-cells with the opposite mAb. The new mAb, MIL8, reacts with a separate epitope on porcine wCD6.     

生长激素释放肽-6缓释微球的制备及其对动物生长的影响

以生物降解材料乳酸乙醇酸共聚物(PLGA,LA-GA 8515)为载体,采用复乳-液中蒸发法制备含生长激素释放肽-6的乳酸乙醇酸共聚物微球,并通过体外药物释放试验评价载药微球的释药特征.结果得到收率、粒径大小和分布及含药量均满意的微球,其中包封率为100%,平均体积径为3.45μm,收率为79%.在37℃、pH7.0的生理等渗缓冲液中,首日释药19.19%,其后以平均日释药3.23%的速度释药25 d.小鼠肌肉注射微球30 d后,累积增重比注射生长激素释放肽-6、生理盐水分别高22.56%(P<0.05)和53.17%(P<0.01).结果表明,生长激素释放肽-6乳酸乙醇酸共聚物微球有望发展成为新型长效制剂.