用SSR技术和混合取样方法估算玉米群体间的遗传距离

The factors affecting the binding characteristics of GBSS with starch granule were studied using a wheat (Triticum aestivum) cultivar Chinese Spring with different temperature treatments. After sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis, we got GBSS concentration by coomassie brilliant blue G-250(CBB G-250) method. The results showed that the temperature affected the binding of GBSS and starch granule. In 50–80℃, the concentration of GBSS unbound from starch increased with the temperature rising, which the maximal concentration was 11.361 μg mL^-1 at 80℃, while that was reduced when the temperature was 85–95℃. Furthermore, Mg²⁺ could also affect the quantity of GBSS unbound from starch. When Mg2+ concentration was lower than 1.75 mmol L^-1, the concentration of GBSS unbound increased. The lower Mg²⁺ concentration, the higher the concentration of GBSS unbound. However, when Mg²⁺ concentration was higher than 2.5 mmol L^-1, it could restrain GBSS unbinding. These results showed that GBSS bound starch granule by non-covalent bonds. The best GBSS extracting conditions were 55 mmol L^-1 Tris-HCl (pH 6.8), 0.75 mmol L^-1 MgCl₂, 2.3% SDS, 5% 2-ME and 10% glycerol, 15 min in boiling water, or 55 mmol L^-1 Tris-HCl (pH 6.8), 0.75 mmol L^-1 MgCl₂, 2.3% SDS, 5% 2-ME and 10% glycerol, 80℃ 30 min. The results are helpful to investigate 3-D structure of biological activated GBSS and mechanism of GBSS binding with starch granule.     

Risk factors for development of sterile haemorrhagic cystitis in canine lymphoma patients receiving oral cyclophosphamide: a case–control study

Sterile haemorrhagic cystitis (SHC) is a known risk of cyclophosphamide treatment; however, most canine reports are case series. This case–control study examined risk factors for SHC in dogs with lymphoma receiving oral cyclophosphamide. Twenty‐two dogs with SHC and 66 control dogs were identified. On univariate analysis, SHC risk factors included age (P = 0.041), induction protocol (P = 0.021) and cumulative cyclophosphamide dose (P = 0.002). On multivariate analysis, increasing cumulative cyclophosphamide dose was associated with increased risk of SHC and the ‘short’ induction protocol (protocol 1) was associated with decreased risk. Controlling for age and induction protocol, odds of SHC increased by 2.21 per 750 mg m^?2 increase in cyclophosphamide dose (P = 0.001). SHC from oral cyclophosphamide is a predominately delayed toxicity resulting from high cumulative doses.     

利用棉绳采集口腔液监测猪伪狂犬病方法的应用分析

为分析使用棉绳采集口腔液监测猪场伪狂犬病(PR)方法的科学性,本研究拟通过实验室水平、动物试验及临床应用3个方面对使用棉绳采集口腔液监测猪场PR这一方法开展应用分析。首先对采样条件进行优化,并通过模拟试验测定棉绳对伪狂犬病病毒(PRV)的释放能力,通过动物试验测定病毒感染后检出时间,最后对临床样品进行检测分析。结果表明:使用直径为1.0 cm的棉绳,在早上喂料前采集口腔液样品,采样时间为20~30 min,可采集到更能满足试验要求的口腔液。病毒释放能力测定显示,棉绳对PRV的释放能力为50%左右,使用棉绳采集口腔液可检测到1个TCID50/0.1 mL的病毒含量。动物试验检测发现,猪群在感染后28 d中除第5天外,口腔液中病原含量均高于鼻拭子中病原含量,口腔液检测效果优于鼻拭子,且口腔液中病毒的检出时间(感染后第1天)早于血液中抗体转阳时间(感染后第7天)。临床样品检测分析结果表明,PRV疫苗免疫后也可通过口腔液检测到疫苗毒,并且存在无法通过口腔液检测感染PRV野毒后稳定猪中带毒的情况,因此口腔液检测方法应结合gE抗体检测,才可综合判断猪群是否为感染群体。综上,本研究优化了口腔液采集方法,并测定了棉绳对口腔液的释放能力和感染后检出时间,表明口腔液可作为较好的监测猪群PR的手段;口腔液监测方法需结合gE抗体检测来综合判断猪群是否为感染群体。     

Treating the locoregional lymph nodes with radiation and/or surgery significantly improves outcome in dogs with high‐grade mast cell tumours

High‐grade canine mast cell tumours (HG‐MCT) have a high rate of locoregional relapse. In this study, dogs with HG‐MCT treated with radiation therapy (RT) were retrospectively evaluated to determine the benefit associated with treating the locoregional lymph nodes (LNs). Forty‐two dogs were included. Variables assessed for association with overall survival (OS) and progression‐free survival (PFS) included WHO stage, tumour location and size, LN irradiation (prophylactic, therapeutic or none), LN treatment (yes or no), LN status at RT (metastatic or nonmetastatic) and RT intent (definitive vs palliative). Lower‐stage disease at irradiation was significantly associated with prolonged median PFS (425 vs 125 days for stage 0 vs 1‐4), and OS (615 vs 314 days for stage 0 vs 1‐4). Having any LN treatment and definitive RT were both significantly associated with prolonged OS. In order to evaluate the role of LN irradiation, dogs were divided into subgroups: (a) stage 0 at irradiation with no LN treatment (n = 14), (b) stage 0 at irradiation with prophylactic LN irradiation (n = 6), (c) stage 0 at irradiation but previously stage 2 (n = 5) and (d) stage >0 at irradiation (n = 17). Prophylactic LN irradiation significantly prolonged PFS (>2381 vs 197 days; group B vs A). Interestingly, dogs that were stage 2 and had LN treatment (C) had prolonged OS vs dogs with negative LNs and no LN treatment (A) (1908 vs 284 days; P = .012). This study confirms that prophylactic and therapeutic LN irradiation in dogs with HG‐MCT is beneficial and improves outcome.     

Prognostic significance of weight changes during treatment of feline lymphoma

The study purpose was to determine the prognostic significance of weight changes during feline lymphoma treatment. A secondary purpose was to compare weight changes according to baseline body weight, cell type and location. Records of 209 cats treated for lymphoma with chemotherapy from 1995 to 2007 were evaluated. Signalment, cell type, lymphoma location, baseline body weight, weight during treatment, and outcome information were collected. Lymphoma specific survival (LSS) was compared according to baseline weight and weight changes during treatment. Weight change over time was compared according to cell type (small versus large), location (gastrointestinal versus non-gastrointestinal) and baseline weight. Cats with large cell lymphoma that lost ≥ 5% body weight at 1 month had significantly shorter LSS than those that gained or had stable weight (P = 0.004). Percentage weight change over time differed significantly according to baseline weight group. These findings demonstrate the prognostic importance of weight loss in feline large cell lymphoma.     

Chemotherapy of Canine Hemangiosarcoma With Doxorubicin and Cyclophosphamide

Sixteen dogs with a histologic diagnosis of hemangiosarcoma were treated with surgery and doxorubicin/ cyclophosphamide. The patients' characteristics, ie, age, size, and breed, were similar to those of previous studies. Historic controls for surgery alone were used to evaluate efficacy of the chemotherapy. The results show a trend of improved survival in dogs with localized disease (Stage I) receiving combination therapy. The median survival was 250 days, with a mean of 403 days. The survival times for dogs with stage I, II, and III disease was also improved with combination therapy, when compared to historical controls treated with surgery alone. The overall median survival was 202 days with a mean of 285 days. Toxicities included mild to moderate neutropenia (9 of 16) and clinical signs, such as lethargy, anorexia, vomiting, diarrhea, and fever (13 of 16). Three dogs had severe neutropenia requiring hospitalization and supportive care. One dog died from sepsis and related complications. Chemotherapy with doxorubicin and cyclophosphamide appears to improve survival with acceptable morbidity in patients with early stage disease. (Journal of Veterinary Internal Medicine 1993; 7:370–376. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

A prospective investigation of the prevalence and prognostic significance of weight loss and changes in body condition in feline cancer patients

The objectives of this study were to prospectively identify and characterize weight loss and changes in body condition in feline cancer patients and to investigate the prognostic significance of these findings. Fifty-seven cats with neoplasia were evaluated. Body condition was assessed with a nine-point scoring system (BCS) and multiple sites were assessed for muscle and fat mass using four-point scoring systems. Feline cancer patients had a mean BCS of 4.4+/-2.1 kg (1=cachectic, 5=optimal, 9=obese). Fat mass was reduced in both sites assessed in 60% of the patients. Muscle mass was reduced at all three sites assessed in 91% of the patients. Feline cancer patients having a BCS <5 had a median survival time (MST) of 3.3 months compared to that of 16.7 months for cats with a BCS of > or = 5 (P=0.008).     

Ac/Ds转座子系统及其在玉米突变体库构建中的应用

Ac/Ds转座子系统是研究玉米功能基因组学的重要工具。Ac/Ds转座子系统以其在基因组中的低拷贝、倾向插入基因外显子、可以在同一基因不同位点造成突变等独特优势,在构建玉米突变体库和进行基因功能鉴定方面具有重要应用前景。综述了Ac/Ds转座子系统的插入特点、转座机制、在玉米突变体库构建中的应用以及我国玉米突变体库的现状,并对我国玉米Ac/Ds突变体库的研究提出展望。     

近红外反射光谱测定玉米完整子粒蛋白质和淀粉含量的校正模型

以玉米完整子粒为实验材料,采用偏最小二乘回归法建立近红外反射光谱测定其蛋白质和淀粉含量的数学模型,光谱预处理结果表明采用矢量归一化和一阶导数+多元散射校正分别建立蛋白质含量和淀粉含量的校正模型效果最佳,外部验证结果证明校正后模型预测结果与化学值之间的相关系数分别达到0.946 9和0.924 0。     

利用候选区域的多模型跟踪算法

跟踪过程中发生的尺度变化、形变、遮挡是导致模型漂移的重要原因。为了克服模型漂移对鲁棒跟踪的影响,本文提出了一种利用多判别式模型和候选区域的跟踪算法。首先,该算法采用候选区域替代传统的滑动采样,适应跟踪过程中目标的位移和尺度变化。接下来,为了提高目标的表征能力,先用预训练网络提取整幅图片的深度特征,再通过感兴趣区域采样层(ROI pooling layer)快速提取每一个候选区域的深度特征,进一步提高跟踪算法的鲁棒性。最后,运用多模型选择机制进行回撤过去错误的模型更新,并通过调整搜索区域实现对目标的重检测,有效抑制了模型漂移对鲁棒跟踪的影响。实验中,本文算法与相关算法在OTB 2013数据库和UAV 20L数据库上进行了对比。结果表明,本文算法在精确度与成功率上均取得了最优性能,并能有效抑制模型漂移对鲁棒跟踪的影响。