Chitosan nanoparticles enhance developmental competence of in vitro-matured porcine oocytes

Oxidative stress is inevitable as it is derived from the handling, culturing, inherent metabolic activities and medium supplementation of embryos. This study was performed to investigate the protective effect of chitosan nanoparticles (CNPs) on oxidative damage in porcine oocytes. For this purpose, cumulus–oocyte complexes (COCs) derived from porcine slaughterhouse ovaries were exposed to different concentrations of CNPs (0, 10, 25 and 50 µg/ml) during in vitro maturation (IVM). Oocytes treated with 25 µg/ml CNPs showed significantly higher levels of GSH, along with a significant reduction in ROS levels compared to control, CNPs10 and CNPs50 groups. In parthenogenetic embryo production, the maturation rate was significantly higher in the CNPs25 group than that in the control and all other treated groups. In addition, when compared to the CNPs50 and control groups, CNPs25-treated oocytes showed significantly higher cleavage and blastocyst development rates. The highest concentration of CNPs reduced the total cell number and ratio of ICM: TE cells in parthenogenetic embryos, suggesting that there is a threshold where benefits are lost if exceeded. In cloned embryos, the CNPs25 group, as compared to all other treated groups, showed significantly higher maturation and cleavage rates. Furthermore, the blastocyst development rate in the CNPs25-treated group was significantly higher than that in the CNPs50-treated group, as was the total cell number. Moreover, we found that cloned embryos derived from the CNPs25-treated group showed significantly higher expression levels of Pou5f1, Dppa2, and Ndp52il genes, compared with those of the control and other treated groups. Our results demonstrated that 25 µg/ml CNPs treatment during IVM improves the developmental competence of porcine oocytes by reducing oxidative stress.     

木豆在贵州亚热带地区的推广应用

着重分析了贵州省亚热带地区近5年木豆引种栽培及推广应用情况和存在的问题,提出了立足市场需求、搞好区域布局、调整品种结构、加强配套技术研发、积极稳妥地有序发展等对策措施。     

怎样辨别板栗伪劣品种苗

板栗 ( Castanea mollissima)原产我国 ,南北均可种植 ,只是不同地域种植不同生态型品种而已。由于南方良种板栗比北方板栗成熟期早 ,可提前满足市场需求 ,且果大、色艳 ,栗实价格高 ;同时 ,板栗抗性强 ,种植易 ,有利退耕还林等特点 ,故我省农民特点是山区农民乐于种植 ,争相发展。但过去一些年 ,我省在板栗发展中却吃了不少“苦头”,主要是伪劣板栗品种苗木之故。近期不少有关种植单位和个人询问果树品种苗木 ,特别是板栗伪劣品种苗的有关问题 ,现述之于下。1　评判板栗伪劣品种的标准从园艺学角度言 ,符合下列标准者为优良品种 ,否则 ,应…     

循环经济下国土资源配置的宏观调控研究

循环经济作为一种新生的经济形态,其实质是生态经济。而在我国人口众多,资源相对贫乏,长期沿用高扩张、高物耗、高污染的粗放型经济发展模式下,国土资源已经不堪重负,故循环经济理念的提倡是实现国土资源宏观调控和合理配置的必然选择。探讨了循环经济与国土资源配置的宏观调控之间的关系,并在此基础上提出了相应的对策和措施。     

Resveratrol supplementation into extender protects against cryodamage in dog post-thaw sperm

Antioxidants have multiple protective roles in a variety of cells and thus can be used to protect sperm against cryo-damage during freezing, which affects fertility. The antioxidant resveratrol (3,5,4-trihydroxytrans-stilbene; RSV) has been reported to protect the animal sperm during cryopreservation, including human sperm. In this study, we assessed the protective effects of RSV supplementation on dog sperm cryopreservation. Semen was collected from four dogs and the effect of different concentrations of RSV (0, 100, 200, and 400 µM) on post-thaw sperm quality was examined. After thawing, sperm motility was assessed using computer-aided sperm analysis, and the structural integrity of the plasma membrane, acrosome, and chromatin was examined. In addition, their mitochondrial activity and gene expression were also assessed. Dog sperm cryopreserved with 200 µM RSV showed significant improvement in post-thaw sperm motility and viability compared with that of the control group (P<0.05). Moreover, RSV-supplemented samples showed significantly higher numbers of sperm with an intact plasma membrane, active mitochondria, and structural integrity of acrosomes and chromatin than that of control samples (P<0.05). Furthermore, gene expression showed that RSV supplemented samples showed lower expression of pro-apoptotic (BAX), reactive oxygen species (ROS) modulator oxidative stress-related (ROMO1) and 8-oxoguanine DNA glycosylase 1 (OGG1) whereas higher expression levels of anti‐apoptotic (BCL2), protamine-2 (PRM2), protamine-3 (PRM3) and sperm acrosome‐associated 3 (SPACA3) genes than control. Our results suggest that RSV, at its optimum concentration, can be efficiently used as an antioxidant in the cryopreservation of dog sperm.     

The effect of astaxanthin supplementation on the post-thaw quality of dog semen

Astaxanthin is a member of the carotenoid family well known for its anti-cancer, anti-diabetic, anti-inflammatory and antioxidant nature. This study was designed to investigate the effects of astaxanthin supplementation of the extender (buffer 2) on post-thaw dog semen quality. Semen from four healthy dogs was collected by digital manipulation twice a week. The ejaculates were pooled, washed, divided into four equal aliquots, diluted with the extender supplemented with different concentrations of astaxanthin (0, 0.5, 1 and 2 µM) and cryopreserved. The results showed that 1 µM astaxanthin was the optimum concentration that led to significantly higher (p < .05) post-thaw motility, kinematic parameters and viability than the other groups. In comparison with the control group, sperm samples supplemented with 1 µM astaxanthin showed significantly higher (p < .05) sperm counts with intact membranes (55.7 ± 0.6% vs. 51.3 ± 0.9%), intact acrosome (58.4 ± 0.7% vs. 53.5 ± 0.6%), active mitochondria (54.9 ± 0.5% vs. 42.6 ± 0.6%) and normal chromatin (67.6 ± 0.9% vs. 61.7 ± 0.6%). Furthermore, astaxanthin-supplemented samples showed significantly lower expression levels (p < .05) of pro-apoptotic (BAX), oxidative induced DNA damage repair (OGG1), oxidative stress-related (ROMO1) genes and higher expression levels of anti-apoptotic (BCL2), and sperm acrosome-associated (SPACA3) genes compared to the control. Thus, supplementation of 1 µM astaxanthin in semen extender results in improved freeze-thaw sperm quality of the dog.     

Acute Phase Response to Surgery of Varying Intensity in Horses: A Preliminary Study

Objective— To evaluate the postoperative inflammatory response of horses to elective surgery of varying intensity.
Study Design— Prospective longitudinal study.
Animals— Horses referred to 2 hospitals for either arthroscopic removal of a unilateral osteochondritic lesion in the tibiotarsal joint (minimal surgical trauma, n=11), correction of recurrent laryngeal neuropathy by laryngoplasty and ventriculectomy (intermediate surgical trauma, n=10) or removal of an ovarian tumor by laparotomy (major surgical trauma, n=5).
Methods— Horses had a thorough clinical examination every day. White blood cell (WBC) counts and concentrations of serum amyloid A (SAA), fibrinogen, and iron were assessed in blood samples obtained before, and 1–3, 5, 7, 9, and 11 days after surgery. Differences in levels of the inflammatory markers between the 3 surgical groups were analyzed using repeated measures ANOVA.
Results— Postoperative concentrations of SAA and fibrinogen were significantly higher in horses that had laparotomy and ovariectomy than in horses that had laryngoplasty and ventriculectomy, or arthroscopy. Iron concentrations decreased to lower levels after intermediate and major surgical trauma than after small surgical trauma. WBC count did not differ between the 3 groups.
Conclusions— Levels of SAA, fibrinogen, and iron reflected the intensity of the surgical trauma, whereas WBC count did not.
Clinical Relevance— Postoperative measurements of SAA, fibrinogen, and iron may be useful for comparing surgical trauma associated with new and established surgical techniques. Moreover, knowledge of the normal postoperative acute phase response is essential, if acute phase reactants are to be used for monitoring occurrence of postoperative infections.