Cryo-scanning Electron Microscopy Discloses Differences in Dehydration of Frozen Boar Semen Stored in Large Containers

In general, freezing in flat plastic polyethylene terephthalate (PET) bags (FlatPacks) at 50°C/min gives better post-thaw viability, in terms of sperm motility and membrane integrity, than does freezing in plastic maxi-straws, probably owing to differences in cryobiology. To test the hypothesis that this better survival post-thaw relates to the degree of sperm dehydration during freezing, the present study investigated the structure of boar semen in a frozen state using cryo-scanning electron microscopy (cryo-SEM) to compare two different packages (FlatPacks and maxi-straws) for single artificial insemination (AI) doses, and three different freezing rates. The semen was split-sample frozen in maxi-straws or FlatPacks (both holding 5 ml) using 3% glycerol as cryoprotectant. Three freezing rates were applied from −5°C to −100°C, namely 2°C/min, 50°C/min and 1200°C/min, the lattermost by plunging the samples into liquid nitrogen (LN₂). The samples were thereafter fractured into LN₂ and larger areas of extra-cellular, unbound frozen water ('ice lakes') were measured to determine the degree of dehydration of the spermatozoa. These areas decreased in size with an increase in cooling rate, the differences in size being more dramatic for maxi-straws than for FlatPacks. Size of ice lakes was also influenced by location within package in relation to cooling rate, the central values being always smaller in maxi-straws than in Flatpacks (p < 0.05 at 2°C/min and 50°C/min) but not at 1200°C/min, which suggested the FlatPack allows for more homogenous freezing of boar semen.     

Morphology of the Dentin Structure of Sloths Bradypus tridactylus: A Light and Scanning Electron Microscopy Investigation

The aim of this study was to describe the dentine morphology of sloths (Bradypus tridactylus). The sloth teeth were removed and prepared for light microscopy (LM) and scanning electron microscopy analyses (SEM). LM revealed two patterns of tubular dentins: an outer with dentinary tubules over the all tooth length and one in the inner part with larger diameter and more spaced tubules, when compared to those present in the outer dentine. These findings were confirmed by SEM, which revealed a tubular pattern in the outer dentine like in humans. The inner dentine displayed pared grouped tubules that were characterized as vascular channels. It can be concluded that this sloth species present two types of dentins: an inner dentin (ortodentin) and an outer dentin characterized as a vascular dentin. This suggests a partial evolutive/adaptive process of this dental tissue, as compared to other mammalian species.     

成年大鼠睾丸微血管构筑的光镜与扫描电镜观察

采用石蜡切片及微血管铸型技术,观察了成年大鼠睾丸微血管的分布与构筑形式.光镜下每个生精小管与六个生精小管相临,微血管则明显得排列在相临生精小管形成的六角形的角缘处.扫描电镜下观察到睾丸表面的微动脉吻合为网格状;这种形式为睾丸表面的生精小管提供了丰富的营养和必要的激素水平;睾丸动脉主支发出走行迂曲的睾丸小动脉,进入睾丸小隔后,再发出管间微动脉,并与管间微动脉相互连接为绳梯状的毛细血管网.睾丸实质内绳梯状的毛细血管网,使每个生精小管都能得到充分的营养和激素供应;睾丸内的动脉迂曲走行,对于维持睾丸低于体内3～5℃的适宜温度,使精子正常产生,具有重要意义.     

A Practical Technique for Electron Microscopy of Buffy Coats in Dogs and Cats

Plastic hematocrit tubes (PHTs) are convenient tools for electron microscopy (EM) of peripheral blood buffy coats, and the PHT‐EM technique is expected to be a practical method for veterinary clinical medicine. In this study, fixatives composed of various concentrations of sucrose, glutaraldehyde, and phosphate buffer (PB) were tested for preparing canine and feline buffy coats. The highest quality images were obtained using a fixative consisting of 2.5% glutaraldehyde in 0.1 m PB, and it was concluded that this method allows clinicians who are inexperienced in histological techniques can conveniently transport buffy coat samples to diagnostic laboratories for analysis by EM.     

Fetal Ependyma in Sheep and Goat. A Scanning Electron Microscopy Study

Morphology of the surface of apical membranes of ependymal cells has been studied in the whole ventricular system of the brain in goat and sheep fetuses using a scanning electron microscope. The surface structure of the ependymal lining surface in fetuses of small ruminants is very similar to that in adult animals. Supraependymal cells were found only in the lower part of the third cerebral ventricle in goat fetuses, but not in sheep fetuses. In small ruminants the ependymal surface is already regionally differentiated within the end of the first half of prenatal development. Fetal ependyma of goats and sheep, unlike the adult ependyma, is characterized by a high secretory activity, which is independent of sex or age of fetuses.     

Seasonal Variation of Plasminogen Activator Activity in Spermatozoa and Seminal Plasma of Boar,Buck, Bull and Stallion

Plasminogen activators (PA) are proteolytic enzymes present in the spermatozoa and seminal plasma of various species. They play a role in the binding of the spermatozoon and its penetration through the layers surrounding the oocyte. Plasminogen activator activity (PAA) is modulated by hormones that have a seasonal variation, such as testosterone and melatonin. The present study investigates the seasonal variation of PA activity in sperm extracts and seminal plasma of four farm animal species: boar, buck, bull and stallion. Semen samples were collected every second week during a 12‐month period and PAA was determined. With respect to sperm enzyme activity, the boar showed a peak from late January until the beginning of April, whereas the activity in the bull was at the highest levels from April until October and gradually declined during autumn and winter period. Plasminogen activator activity of stallion spermatozoa peaked during March and April, and remained low throughout the rest of the year, whereas in the buck sperm, PAA increased from late October until the end of January. No biologically significant variation was detected regarding the seminal PAA activity in any of the species studied. While seasonality of reproduction is typically studied from the female perspective, the present data provide compelling information about a factor that may affect the reproductive ability of the male.     

应用电镜技术对犬腺病毒及其免疫球蛋白的检测

应用电镜技术及免疫金电镜技术检测犬腺病毒及驴抗犬腺病毒免疫球蛋白（Ｉｇ）。实验结果证明了由驴所产生的Ｉｇ对犬腺病毒具有较强的特异性反应,对犬肝炎、犬喉气管炎等疫病具有良好的治疗和预防作用。     

应用电镜技术快速检测培养细胞中的支原体污染

应用电镜技术可快速准确地检测培养细胞中的支原体污染。通过高速离心浓缩样品,负染色后电镜观察,可在30min内做出判定,方法快速、简便、准确。     

扫描及负染电镜在兔脑炎原虫病诊断中的应用

12只临床表现头颈歪斜、昏睡、震颤、局部或全身轻瘫的可疑为兔脑炎原虫病的獭兔 ,对其肾脏皮髓交界和尿沉渣分别进行了扫描电镜和负染电镜观察 ,看到了大小为 1～ 1 .5× 1 .4～ 2 .5μm,形态呈卵圆形和杆状的兔脑炎原虫。阳性检出率为 1 0 0 %。说明扫描及负染电镜术是诊断兔脑炎原虫病的一种较为可靠的技术。     

家鸡蛋壳组织结构的扫描电镜观察

用扫描电子显微技术对家鸡蛋壳结构进行研究的结果，进一步直观形象地丰富了我们在这个领域的知识。     

应用电镜技术对狂犬病不同毒株的形态学研究

将狂犬病固定毒ＣＴＮ株（中国济南株）、ＣＶＳ株（国际标准攻击毒株）、ＥＲＡ株（兽用疫苗弱毒株）,分别在小鼠脑组织增殖及ＥＲＡ毒株在ＢＨＫ２１传代细胞增殖,通过超薄切片和负染色制备样品,电镜观察。结果发现,在相同鼠脑组织中,ＣＴＮ株病毒粒子比较难查找,而ＣＶＳ株和ＥＲＡ株较易被发现。另外,在不同毒株的脑组织和细胞培养物另还发现了大量的非典型粒子,诸如削了顶的粒子以及锥形、柱形等形态,同时还发现了胞浆包涵体。通过试验,我们认为：⑴典型病毒数量与免疫原性呈正相关。⑵在观察鼠脑细胞中的病毒时,发现有神经髓鞘部位是难以找到病毒粒子的。⑶狂犬病病毒粒子存在于宿主细胞浆内,核内未发现。     

A Light and Electron Microscopic Study of Developing Bovine Sympathetic Ganglia

This study concentrated on the histogenesis of bovine sympathetic ganglia, especially the development of the capsule, the interaction of sympathoblasts and supporting cells, and the ultrastructural detail of developing sympathoblasts. For this purpose 1st thoracic ganglia from 19 embryos and foetuses were collected and separated into 4 groups. The methods of study involved light and electron microscopy. From the study it was concluded that for neuronal development a functional interaction was necessary with satellite and Schwann cells, that the capsule had a role in maintaining neuronal homeostasis, and that sympathetic neurons displayed a number of morphologically distinct forms before reaching maturity.     

用免疫金标记电镜技术检测病毒及其抗体

以ILTV、CDV、CAV、FPV4种病毒作代表株,应用免疫金标记电镜技术,借鉴中和试验及沉淀反应方法对这4种病毒及其抗体进行检测。证明该技术简单可靠,可获得高分辩率、直观、准确、特异的标记,且可一次性对病毒及其抗体进行定性和定量。     

松辽黑猪新品系及其与长白山野猪杂交一代生长肥育性能比较

选择松辽黑猪新品系后备育成猪和长白山野猪与松辽黑猪的杂交一代育成猪各20头,开展饲养试验、屠宰测定、肉质分析以及氨基酸、脂肪酸、血液相关指标的测定比较。结果表明,日增重：松辽黑猪新品系要比长野猪杂交一代高5．49％,差异不显著（P〉0．05）;料肉比：提高19．15％,差异显著（P〈0．05）。长野松杂交猪的瘦肉率比松辽黑猪新品系低3．8％,差异显著（P〈0．05）,肌内脂肪含量松辽黑猪则比长野松杂交猪提高32．25％,有极呈著差异（P〈0．01）。饱和脂肪酸（硬脂酸）含量松辽黑猪比长野松杂交猪高15．43％,差异显著（P〈0.05）：多不饱和脂肪酸亚麻酸的含量松辽黑猪则比野松杂交猪高23．15％,也有显著性差异（P〈0.05）。血液中三碘甲状原氨酸（T3）含量,长野松杂交猪比松辽黑猪提高了98．4％,差异极显著（P〈0.01）;而血清白蛋白和谷草转氨酶含量长野松杂交猪显著高于松辽黑猪（P〉0．05）,胆固醇含量长野松杂交猪则比松辽黑猪降低了10．91％,但没有达到显著性差异（P〉0．05）。