Endoscopically guided nasojejunal tube placement in dogs for short‐term postduodenal feeding

Objective – To evaluate a method for endoscopically guided nasojejunal tube placement allowing short‐term postduodenal feeding and chyme withdrawal in dogs. Design – Pilot study. Setting – University teaching hospital. Animals – Three healthy Beagle dogs with jejunal nipple valve fistulas. Interventions – After the dogs were anesthetized, an 8 Fr, 250‐cm polyvinyl chloride catheter was advanced through a gastroscope into the jejunum. Correct jejunal placement was established using endoscopic visualization and confirmed by fluoroscopy and radiography. The proximal end of the tube was pulled out through 1 nostril and sutured to the skin of the forehead. Thereafter, jejunal feeding was administered for 4 days. Follow‐up examinations included daily confirmation of the tube's position using radiography, physical examination, and blood analyses. Withdrawal of jejunal chyme was performed after jejunal and oral feeding. Measurements and Main Results – Fluoroscopic examination confirmed that endoscopic visualization alone allowed correct jejunal placement. During a 4‐day postduodenal feeding period, repeated radiographic examination revealed stable positioning of the tubes within the jejunum with minor cranial displacement. The tubes were functional throughout the study without causing identifiable problems. Repeated physical examinations and blood analysis showed no abnormalities. We were able to administer the daily caloric requirements as a liquid diet. Jejunal chyme was successfully withdrawn via the tube. Conclusions – Endoscopically guided nasojejunal tube placement was shown to be a minimally invasive, well‐tolerated method for short‐term jejunal feeding in healthy dogs. This technique is a viable option for dogs requiring jejunal feeding but not laparotomy. The feasibility of chyme sampling is another unique application of the procedure.     

lncRNA在顶复门原虫感染中的作用机制

长链非编码RNA(long noncoding RNA,lncRNA)是一种核酸长度>200 nt、不编码或具有有限编码能力的RNA,早期一直被认为是遗传暗物质,但伴随分子生物学技术的进步,越来越多的lncRNAs被发掘。研究表明,lncRNA作为基因表达的关键调控因子,能在组蛋白修饰、转录调控和转录后调控等方面影响基因表达,几乎参与所有的细胞生物学过程。顶复门原虫是一类专性胞内寄生虫,入侵机制复杂,对顶复门原虫与宿主的互作研究已成为新型抗虫药物的研发基础。近年来研究发现,lncRNA作为一类新型调控因子广泛参与到顶复门原虫与宿主细胞相互作用中,包括感染免疫、发育分化和信号传导等细胞生物学过程,既可帮助宿主抵御寄生虫入侵,也可协助寄生虫在胞内增殖发育,对疾病的发生发展具有重要的调控作用。笔者通过对lncRNA的生物学分类及其在细胞生理过程中的主要功能进行概述,综合近年来lncRNA在以弓形虫、疟原虫和隐孢子虫为主要代表的顶复门原虫的相关研究,系统梳理了lncRNA在宿主免疫反应、寄生虫发育分化和表观遗传调控等方面的作用机制,以期为顶复门原虫致病机理研究及高效防控技术研发提供新的思...     

饲用燕麦品种在晋北农牧交错区的生产性能和营养价值研究

在干旱半干旱地区，以17个饲用燕麦品种作为研究对象，连续3年观测其株高、干草产量、营养性状等指标，利用近红外光谱技术对干物质、酸性洗涤纤维、中性洗涤纤维和可溶性糖4个营养性状指标进行测定分析，并采用灰色关联度分析方法进行综合评价。结果表明：①青引2号的生育天数仅86 d，而林纳、锋利和定燕2号的生育天数均为105 d。②至乳熟期，参试品种中定燕2号的平均株高最高，而白燕19号、魁北克、KONA和早熟1号4个品种在乳熟期的平均株高均在90 cm以下，与其他参试品种间差异显著（P<0.05）。③至乳熟期，甜燕二号品种的干草产量迅速增加，平均产量较高，与早熟1号、白燕19号、林纳、定燕2号、青引2号和甜燕麦品种间差异显著（P<0.05），且这6个品种的平均干草产量均在7 000 kg·hm-2以下。④各品种的营养成分分析结果显示，在3个不同生育时期，参试品种的干物质含量均在90%以上（除林纳乳熟期外）；各品种的中性洗涤纤维和酸性洗涤纤维含量不同时期差异明显；可溶性糖含量在开花期各品种间存在较明显差异。⑤17个参试品种中，以定燕2号品种的主穗长最长，KONA品种的穗铃数最多，穗粒数以魁北克品种的数量最多，穗粒重以白燕19号品种最高，千粒重以甜燕麦品种最高。综合分析结果表明，甜燕二号、定燕2号、林纳、魁北克、甜燕麦5个品种的综合生产力最优，适宜在本地区优先推广利用。