Activation of Mouse Oocytes Following Intracytoplasmic Injection of Chicken Sperm Extract

The cytosolic factor from the sperm of a wide variety of species has been reported to induce [Ca²⁺]i increase and/or activation in oocytes. Although many species have been studied, there is no data available on the chicken sperm factor responsible for activation of oocytes. This study was aimed to verify the activation of mouse oocyte by intracytoplasmic injection of chicken sperm extract (CSE). Survival rate of oocytes without rupture or lytic degeneration following injection was greater than 80% regardless of the presence or absence of CSE. Among the intact oocytes, activation rates following injection were 27.5% (11 of 40) in the sham operation group. Injection of CSE resulted in significantly higher activation rates in the 1/10 dilution group (57.8%, 26 of 45) compared with the sham operation group (p = 0.0045). Calculated amount of injected sperm extract of 1/10 dilution of CSE was equivalent of 12 chicken sperm. When the 1/10 diluted mouse sperm extract (MSE) was injected, survival rate of injected oocytes and activation rate of the survived oocytes was 82% (41 of 50) and 78% (32 of 41), respectively. Activation rate of MSE‐injected oocytes was a little but significantly higher than that of CSE‐injected oocytes (p < 0.037). In conclusion, it suggests that CSE can activate the mouse oocyte and that oocyte activating sperm factor(s) may be common between avian and mammal.     

Evaluation of a Neck Mounted 2‐Hourly Activity Meter System for Detecting Cows About to Ovulate in Two Paddock‐Based Australian Dairy Herds

Two studies were conducted to assess the performance of a commercially available neck‐mounted activity meter to detect cows about to ovulate in two paddock‐based Holstein‐Friesian dairy herds. The activity monitoring system recorded cow activity count in 2‐hourly periods. Study I investigated the ability of the system to detect cow ovulatory periods in dairy herds managed in two different Australian environments and breeding systems using five activity alert algorithms. Herd 1 consisted of approximately 130 milking cows calving year‐round in a sub‐tropical environment and kept in a single dry lot paddock. Herd 2 consisted of approximately 400 milking cows calving seasonally in a temperate climate and fed pasture by rotation through multiple grazing paddocks. Ovulatory periods and non‐ovulatory days were identified using milk progesterone monitoring alone or in combination with ovarian ultrasonography; using these ‘gold standards’ 141 and 135 ovulatory periods were identified in 64 and 135 cows in Herds 1 and 2 respectively. Sensitivity of the activity monitoring system for detecting cow ovulatory periods ranged from 79.4% to 94.1%, specificity from 90.0% to 98.2% and positive predictive value from 35.8% to 75.8%. Study II investigated the ability of the activity meter system to predict the timing of ovulations in paddock‐based pasture‐fed dairy cattle (Herd 2). The time of ovulation was estimated by repeat trans‐rectal ovarian ultrasonography at approximately 0, 12, 24 and 36 h after artificial insemination (AI). The mean times (±SD) from onset and end of increased activity to ovulation were 33.4 ± 12.4 and 17.3 ± 12.8 h respectively (n = 94). Fifty per cent of cows (n = 47) ovulated within the 8‐h period between 30 to 38 hs after the onset of increased activity, 76.6% (n = 72) within the 16 h between 24 to 40 h, 85.1% (n = 80) within the 24 h between 18 and 42 h and 90.4% (n = 85) within the 32 h from 19 to 51 h after the onset of increased activity. Results from these studies show that in paddock‐based dairy cows in two diverse management systems, this neck‐mounted activity meter system detects high proportions of cows that are about to ovulate and provides a useful indication of when ovulation is likely to occur. However, the specificities and positive predictive values using the algorithms assessed may be lower than desirable.     

Design and fabrication of topologically complex, three-dimensional microstructures

Two concepts for use in the fabrication of three-dimensional (3D) microstructures with complex topologies are described. Both routes begin with a two-dimensional (2D) pattern and transform it into a 3D microstructure. The concepts are illustrated by use of soft lithographic techniques to transfer 2D patterns to cylindrical (pseudo-3D) substrates. Subsequent steps-application of uniaxial strain, connection of patterns on intersecting surfaces-transform these patterns into free-standing, 3D, noncylindrically symmetrical microstructures. Microelectrodeposition provides an additive method that strengthens thin metal designs produced by patterning, welds nonconnected structures, and enables the high-strain deformations required in one method to be carried out successfully.     

锥虫抗药性机制的研究进展

为了较全面地了解锥虫抗药性机制的研究进展,综述了国内外有关报道。锥虫抗药性形成的机制主要表现在三方面,即锥虫体内酶的活性（或含量）发生变化,抗药株虫体的苹果酸酶、锥虫硫酮还原酶或鸟氨酸脱羧酶等酶的活性明显升高;锥虫细胞膜上的特异载体,即细胞膜上转运腺苷酸和腺苷的Ｐ２载体发生改变,药物进入虫体受阻;虫体的抗药基因被激活或基因发生重组、突变或扩增。本文还总结了锥虫抗药性机制研究中存在的问题及今后的研究     

A comparison of two grassland-based systems for autumn-calving dairy cows of high genetic merit

A full lactation study compared the performance of autumn‐calving dairy cows of high genetic merit under two contrasting systems of milk production: high forage (HF) and high concentrate (HC). During the winter, animals on system HF were offered a silage with a high feeding value characteristics, supplemented with 5·5 kg of concentrate [crude protein content of 280 g kg^?1 dry matter (DM)] through an out‐of‐parlour feeding system. From 14 March, these animals were given increasing access to grazing, achieving 24‐h turnout on 15 April. Thereafter, until day 305 of lactation, these animals were offered a large daily herbage allowance (23·0 kg grass DM cow^?1, measured above a height of 4·0 cm), supplemented with 0·5 kg d^?1 of a ‘high‐magnesium’ concentrate. During the winter, animals on system HC were offered a silage of medium feeding value, mixed with ≈14·0 kg of concentrate d^?1 (crude protein content of 202 g kg^?1 DM) in the form of a complete diet. These animals commenced grazing on 9 April, achieving 24‐h turnout on 18 April. From 18 April until 9 June, daily herbage allowances and concentrate feed levels were 17·0 kg DM and 5·0 kg respectively; thereafter, and until day 305 of lactation, these daily allowances were reduced to 15·0 kg of herbage DM and 4·0 kg of concentrate. Animal performance during the first 305 days of lactation for systems HF and HC, respectively, were as follows: total concentrate DM inputs, 842 and 2456 kg; total silage DM intakes, 2205 and 1527 kg; total grass DM intakes, 3019 and 2044 kg; total feed DM intake, 6061 and 6032 kg and total milk output, 7854 and 8640 kg. Total milk output per cow with system HF was 786 kg lower than for system HC, despite similar total DM intakes, suggesting a greater total nutrient requirement with the former to support a given milk production. However, the study confirms that relatively similar levels of animal performance can be achieved from systems based on very different sources of nutrient supply.     

不同蛋白质水平日粮对哺乳期奶牛生产和血液代谢产物的影响

试验选择90头秋季荷斯坦奶牛,包括45头初产奶牛和45头经产奶牛（经产胎次平均为3．1）,随机分到3个蛋白水平日粮组,以干物质为基础蛋白（CP）含量分别为114、144和173g·kg^-1,饲喂到哺乳150d。151d时每个蛋白处理中1／2的奶牛改变日粮蛋白水平。日粮蛋白水平114g·kg^-1组中1／2的奶牛饲喂日粮蛋白水平增加至144g·kg^-1;日粮蛋白水平144g·kg^-1组中1／2的奶牛饲喂蛋白水平增加至173g·kg^-1;日粮蛋白水平173g·kg^-1组中1／2的奶牛饲喂蛋白水平降低到144g·kg^-1;     

Cyclooxygenases 1 and 2 inhibition and analgesic efficacy of dipyrone at different doses or meloxicam in cats after ovariohysterectomy

ObjectiveTo evaluate the cyclooxygenases (COX) inhibition, adverse effects and analgesic efficacy of dipyrone or meloxicam in cats undergoing elective ovariohysterectomy.Study designProspective, blinded, randomized, clinical study.AnimalsA total of 30 healthy young cats.MethodsThe cats were randomly assigned to three postoperative groups: D25 (dipyrone 25 mg kg^?1 every 24 hours), D12.5 (dipyrone 12.5 mg kg^?1 every 12 hours) and M (meloxicam 0.1 mg kg^?1 every 24 hours). In the first 24 hours, the drugs were administered intravenously (IV), and then orally for 6 (dipyrone) or 3 days (meloxicam). Prostanoids thromboxane B₂ and prostaglandin E₂ concentrations served as indicators of COX activity and, with physiological variables and pain and sedation scores, were measured for 24 hours after first analgesic administration. Rescue analgesia (tramadol, 2 mg kg^?1 IV) was provided if Glasgow feline composite measure pain scale (CMPS-Feline) ≥5. Laboratory tests included symmetric dimethylarginine and adverse effects were evaluated regularly up to 7 and 10 days after surgery, respectively. Parametric and nonparametric data were analyzed with two-way anova and Kruskal-Wallis tests, respectively (p < 0.05).ResultsIn the first half hour after analgesic administration, COX-1 activity was close to zero and remained significantly lower than before drug administration for 24 hours in all groups. The inhibition of COX-2 activity was significant for 30 minutes in all groups and up to 4 hours in group M. No alterations in laboratory tests or significant adverse effects were observed. Pain scores and need for rescue analgesia did not differ statistically among groups.ConclusionsDipyrone at both doses and meloxicam provided a nonselective inhibition of COX-1 and -2 activities and effective analgesia without causing significant adverse effects or laboratory tests alterations.Clinical relevanceDipyrone at both doses provides equally effective analgesia without causing adverse effects in cats undergoing ovariohysterectomy.