华支睾吸虫童虫体表发育的扫描电镜观察

利用扫描电镜观察比较了华支睾吸虫５天童虫至３０天成虫的形态及体表的发育变化。５天童虫前１／３部分仍呈筒状，其余部分呈扁平。１０天以上的童虫及成虫，整个虫体呈扁平状。虫体表为网絮状结构且被有一定数量的体棘和乳突。体棘可分为四尖棘、三尖棘、二尖棘和单尖棘。乳突可分为带纤毛的结节状乳突、中央带小结的皮层呈同心圆隆起的乳突、较大的圆丘形乳突、中央带１至２个小结的花瓣样乳突。体棘随童虫的发育逐渐减少，至３０天成虫已完全消失。而乳突随虫体发育逐渐增大且数量增加，尤其是在口腹吸盘唇上及附近体表。     

Retention in Glass Bead Columns as a Measure of Leucocyte Adhesiveness

Erythrocyte sedimentation significantly influenced test results when leucocyte retention in glass bead columns was used as a measure of leucocyte adhesiveness. In blood with elevated ESR, this influence was especially evident. Erythrocyte sedimentation highly increased leucocyte retention in vertical columns with a downward flow, whereas in slightly tilted columns with an upward flow, the retention was reduced. The error in measurements caused by erythrocyte sedimentation could be corrected by means of the haematocrit values in samples and eluates. Correction was better for results obtained with slightly elevated than with vertical columns. The granulocyte retention rates increased with increasing sample size, whereas lymphocyte retention remained constant.     

结膜吸吮线虫成虫扫描电镜观察

本文报告由人体获得的结膜吸吮线虫(Thelazia callipaeda)成虫的扫描电镜观察结果。叙述了雌雄虫头部结构、体表隆起物以及表皮皱摺和棘等的特征和分布情况。     

A Study of Platelet Retention by Glass Bead Columns (''Platelet Adhesiveness'' in Normal Subjects)

S ummary . Platelet adhesiveness tests using glass bead columns were performed in 54 normal subjects. Native blood was forced through the columns by a syringe pump at a flow rate of 6 ml/min, and effluent blood was collected in four aliquots of 2 ml each. The first two aliquots demonstrated a progressive increase in per cent platelet adhesiveness with maximum adhesiveness achieved in the second aliquot. The third and fourth aliquots showed decreased adhesiveness with a progressive broadening of the range of normal. In 11 of the 54 normal subjects the fourth aliquot of effluent blood contained more platelets than the original whole blood and indicated that platelets previously retained by the column were being returned to the effluent. The per cent platelet adhesiveness in the first aliquot did not vary with the platelet count. However, the absolute number of platelets retained by the column increased as the platelet count increased. Moreover, the number of platelets retained from a given aliquot was directly proportional to the number of platelets retained from previous aliquots. The return of platelets to the effluent in the fourth aliquot was associated with the smallest number of platelets retained from the first three aliquots. Adenosine inhibited the retention of platelets by glass bead columns. Retention of platelets by glass bead columns appears to be determined by platelet adhesion to glass surfaces, platelet to platelet aggregation due to released ADP, and spontaneous platelet disaggregation which becomes evident when the initial number of retained platelets provides an insufficient amount of ADP to sustain aggregation.     

肝硬化患者血小板功能变化分析

本文测定了肝硬化患者的血清小板粘附与聚集功能并与正常对照比较，结果发现，肝硬化患者血小板粘附与聚集功能均显著低于正常，且下降程度与肝功能Ｃｈｉｌｄ分级一致，提示肝硬化患者的出血倾向有血小板功能异常参与，且肝功能损害可能为血小板功能异常的主要原因。     

我国七种白蛉咽甲的超微结构研究

目的研究不同地域的7种白蛉(白蛉属5种,司蛉属2种)咽甲内侧壁的超微结构.方法采用扫描电子显微镜进行咽甲超微结构的分析.结果白蛉咽甲的内侧壁由一些齿形结构和横嵴组成,齿形结构和横嵴的形状、数目以及排列方式在各蛉种间表现不同.结论不同种属的白蛉咽甲在超微结构上有明显的差异,可为蛉种鉴定提供形态学依据.     

The Design of a Reflection Electron Energy Loss Spectrometer Attachment for Low Voltage Scanning Electron Microscopy

This paper presents the design of a reflection electron energy spectrometer (REELS) attachment for low voltage scanning electron microscopy (LVSEM) applications. The design is made by carrying out a scattered electron trajectory ray paths simulation. The spectrometer attachment is small enough to fit on the specimen stage of an SEM, and aims to acquire nanoscale spatially resolved REELS information. It uses a retarding field electrostatic toroidal sector energy analyzer design, which is able to lower the kinetic energies of elastically backscattered electrons to pass energies of 10 eV or less. For the capture of 1 keV BSEs emitted in the polar angular range between 40 to 50°, direct ray-tracing simulations predict that the spectrometer attachment will have an energy resolution of around 0.4 eV at a pass energy of 10 eV, and 0.2 eV at a pass energy of 5 eV. This predicted performance will make it a suitable REELS attachment for SEMs that use field emission electron sources.     

Scanning Electron Microscopy with Samples in an Electric Field

The high negative bias of a sample in a scanning electron microscope constitutes the “cathode lens” with a strong electric field just above the sample surface. This mode offers a convenient tool for controlling the landing energy of electrons down to units or even fractions of electronvolts with only slight readjustments of the column. Moreover, the field accelerates and collimates the signal electrons to earthed detectors above and below the sample, thereby assuring high collection efficiency and high amplification of the image signal. One important feature is the ability to acquire the complete emission of the backscattered electrons, including those emitted at high angles with respect to the surface normal. The cathode lens aberrations are proportional to the landing energy of electrons so the spot size becomes nearly constant throughout the full energy scale. At low energies and with their complete angular distribution acquired, the backscattered electron images offer enhanced information about crystalline and electronic structures thanks to contrast mechanisms that are otherwise unavailable. Examples from various areas of materials science are presented.     

我国七种白蛉咽甲的超微结构研究

目的　研究不同地域的7种白蛉 (白蛉属5种,司蛉属2种)咽甲内侧壁的超微结构。　方法　采用扫描电子显微镜进行咽甲超微结构的分析。　结果　白蛉咽甲的内侧壁由一些齿形结构和横嵴组成 ,齿形结构和横嵴的形状、数目以及排列方式在各蛉种间表现不同。　结论　不同种属的白蛉咽甲在超微结构上有明显的差异 ,可为蛉种鉴定提供形态学依据     

The Influence of Age,Sex, and the Use of Oral Contraceptives on the Inhibitory Effects of Endothelial Cells and PGI2 (Prostacyclin) on Platelet Function

The inhibitory effects of human endothelial cells (ECM) and PGI₂ (prostacyclin) on platelet function have been examined in 60 healthy subjects. 5 groups were studied. I. 10 women (19–33 yrs.); II. 10 women (21–31 yrs.) using combined oral contraceptives; III. 10 postmenopausal women (45–66 yrs.); IV. 20 men (24–48 yrs.) and V. 10 men (48–71 yrs.). Spontaneous platelet aggregation in platelet-rich plasma (PRP) was commonly observed in groups II, III, and V. This was prevented when PRP was incubated with ECM, aspirin (ASA), or PGI2. ADP-induced platelet aggregation (PA) was always reduced by ECM, but significantly less in groups II and III. Collagen-induced PA was inhibited by ECM, but less in groups I, II, III and V than in young men (IV). ECM significantly reduced collagen-induced prostaglandin (MDA) production in platelets. Again, the inhibitory effect was significantly reduced in groups II and III. Platelet factor 3 activity, measured after exposure of PRP to ADP, was significantly reduced by ECM, but was significantly less in groups II, III, and V than in group I. Less of an inhibitory effect of PGI₂ upon ADP-induced PA was shown by all groups of females than by the two groups of males.     

巴尔通体Ⅰ、Ⅱ代扫描透射电镜观察

目的探寻巴尔通体培养中子代不如原代长得好、甚至不长的原因。方法收集培养中的Ⅰ代、Ⅱ代巴尔通体菌用扫描、透射电镜观察其超微结构。结果扫描电镜见多个菌缠绕成团，菌体密集。用超声波冲击后有少量孤立的巴尔通体菌似圆球形，外围呈云雾状，中间凹陷。透射电镜见Ⅰ代菌细胞数量多、体积大、饱满，胞膜完整，Ⅱ代数量少，菌细胞出现畸形、衰退，胞膜不完整。结论菌体之间有相互缠绕、聚集、不易分开现象，这是否与它的侵袭、致病性有关，需进一步探讨;传代后原来的生长条件不适合其生长，进一步研究相适宜的培养基很有必要。     

Hemodynamic Effects on Thrombogenesis and Platelet Aggregation in Spontaneously Hypertensive Rats

The present study was conducted to investigate the effect of hypertension on the formation of arterial thrombus in the rat femoral artery. The time required to establish the thrombus following endothelial injury in spontaneously hypertensive rats (SHR) was extremely prolonged. Pretreatment with prazosin which lowered the blood pressure near the level in normotensive Wistar Kyoto (WKY) rats, significantly shortened the thrombogenesis time, but it was still longer than that in WKY rats. Platelet aggregation in response to collagen with washed platelets and whole blood was reduced in SHR with and without hypotensive treatment, in comparison with that in WKY rats. Prazosin did not affect the platelet aggregability. Therefore, the decreased platelet aggregation was considered to be responsible for the delayed thrombus formation in hypotensively treated SHR. These results suggested that high blood pressure, mainly, interferes with the establishment of thrombus directly. Hypoaggregability of platelets is likely to be partly involved in the prolongation of thrombogenesis in SHR.     

The Small-Intestinal Mucosa in Patients with Crohn's Disease Assessed by Scanning Electron and Light Microscopy

Small-intestinal mucosal biopsy specimens obtained by a Watson capsule were, assessed by light (LM) and scanning electron (SEM) microscopy in 18 patients with various sites of Crohn's disease and in 6 healthy controls. By means of LM. partial villous atrophy of the upper small-intestinal mucosa was assessed in six patients. With the use of SEM a further seven patients were shown to have mucosal abnormalities of possible clinical significance. These specimens showed a convoluted villous pattern at low-power SEM and some also enterocyte irregularity, bulging, and surface ultrastructural distortion at medium- and high-power SEM. The medium- and high-power mucosal alterations were unevenly distributed. The high prevalence of abnormalities of the upper small-intestinal mucosa in patients with Crohn's disease elsewhere in the gastrointestinal tract adds further weight to the concept of a diffuse involvement along the entire gastrointestinal tract in Crohn's disease.     

Combining Micro-Raman Spectroscopy and Scanning Electron Microscopy Mapping: A Stony Meteorite Study

Meteorite characterisation represents a privileged and unique opportunity to increase our knowledge about the materials composing the Universe and, particularly, the Proto Solar System. Moreover, meteorites studies evolve contextually with the development of analytical technologies. In the present paper, the results from an unclassified stony meteorite (chondrite) characterisation have been reported on the basis of the innovative analytical protocol presented here. Advanced Mapping by micro-Raman Spectroscopy and Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy have been combined to disclose molecular and elemental features on the same regions sample at a micrometric resolution. Thanks to their non-destructive properties, the mapping tools of both instruments have been applied to single chondrules analysis and the best match between the mineralogical information and the chemical composition has been obtained. This combined approach proved to be highly suitable in disclosing the crystallinity features of the phases, with in-depth spatial and morphological details too.     

Concentration of SARS-CoV-2-Infected Cell Culture Supernatants for Detection of Virus-like Particles by Scanning Electron Microscopy

There is currently a need for new rapid viral diagnostic electron microscopy methods. Although the gold standard remains the transmission electron microscopy (TEM) negative staining method for electron microscopic examination of samples containing a virus, difficulties can arise when the virus particle content of the sample that has to be examined is poor. Such samples include supernatants of virus-infected cells that can be difficult to examine, as sometimes only a few virus particles are released in the culture medium upon infection. In addition to TEM, scanning electron microscopy (SEM) can also be used for visualizing virus particles. One advantage of SEM over TEM is its ability to rapidly screen several large specimens, such as microscopy slides. In this study, we investigated this possibility and tested different coating molecules as well as the effect of centrifugation for analyzing SARS-CoV-2-virus-infected cell culture supernatants deposited on microscopy glass slides by SEM. We found that centrifugation of 25XConcanavalinA-coated microscopy glass slides in shell vials provided an improved method for concentrating SARS-CoV-2-virus-infected cell supernatants for virus-like particle detection by SEM.     

Scanning electron microscopy analysis of erythrocytes in thromboembolic ischemic stroke

Introduction: Erythrocytes play an important role in hemostasis and disease conditions. During ischemic stroke, erythrocytes undergo oxidative and proteolytic changes resulting in a changed cellular rheology. Methods: Blood samples were obtained from controls and thromboembolic ischemic stroke patients (within 48 h of stroke). The ultrastructure of erythrocytes was compared, using a scanning electron microscope (SEM). Abnormal morphology included codocytes, knizocytes, stomatocytes, and echinocytes. Percentage of abnormal cells was calculated, and the analyses were performed using the statistical program NCSS with the level of significance set at 0.05. A t‐test was carried out to compare the data from the erythrocyte counts of stroke patients with that of the control subjects. Results: Ultrastructural SEM results showed that there are a large percentage of erythrocytes in healthy individuals that do not have a typical discoid shape, when studying the cells using a high magnification electron microscope. Furthermore, analysis showed that variation in shape is so subtle that it is not clearly visible using a typical light microscopy blood smear analysis. Thromboembolic ischemic stroke patients presented with a significant amount of erythrocytes with abnormal morphology. Conclusion: We suggest that in healthy individuals, a typical smear would contain several nondiscoid‐shaped erythrocytes, only clearly visible at high magnification. However, thromboembolic ischemic stroke does significantly impact erythorcyte shape, and this change in morphology may result in an impaired microcirculation, as well as impaired oxygen carrying capacity. This changed morphology may further complicate the restoring of homeostasis caused by acute thromboembolic stroke.     

Platelet activation by a novel solid-phase agonist: effects of VWF immobilized on polystyrene beads

The interaction between platelets stirred in suspension and VWF immobilized on polystyrene beads was studied. Platelets aggregated and released ATP in response to stirring with VWF beads. Closer examination of the interaction using transmission electron microscopy revealed that the platelets did not simply aggregate with one another but initially adhered to the beads and spread. Platelets in suspension then bound to the bead-adherent platelets forming layers of platelets associated with each bead. The VWF bead-induced platelet activation was com-pletely inhibited by addition of monoclonal antibody (mAb) to GPIb or GPIIb/IIIa. In addition, the activation response was inhibited in the presence of aspirin, indomethacin or the thromboxane receptor antagonist BM13.177, demonstrat-ing a dependence on an intact cyclo-oxygenase pathway.   Platelet function studies were carried out on 30 patients with a history of mild bleeding using conventional optical aggregation and VWF bead-induced platelet activation. 12 patients were abnormal by conventional optical aggregometry, whereas 27 patients showed depressed ATP release in response to VWF beads. The results suggest that easily-bruised patients may have a platelet function defect rather than a vascular-based abnormality and that VWF bead-induced platelet activation is a more sensitive test for detecting platelet dysfunction.     

蓝氏贾第鞭毛虫滋养体染色体扫描电镜观察

目的电镜观察蓝氏贾第鞭毛虫滋养体的染色体数目及形态。方法用改良TYI-S-33培养基培养贾第虫滋养体。制备分散度较好的染色体玻片标本,对玻片标本进行扫描电镜常规处理,扫描电镜观察。结果在扫描电镜下观察到了蓝氏贾第鞭毛虫滋养体的染色体,染色体数目为2n=10条,1号染色体为亚中央着丝粒染色体,2号、3号、4号、5号为端着丝粒染色体。结论通过电镜观察认为蓝氏贾第鞭毛虫滋养体的染色体核型公式为2n=10=2sm+8t。     

Histoenzymological Light and Electron Microscopic Localization of Carbonic Anhydrase in the Rat Superficial Pineal Gland

A histoenzymological method for demonstration of carbonic anhydrase (CA) was used for cryostat sections of superficial rat pineal gland. Light and electron microscopic analysis showed a high concentration of this enzyme in stellate cells, particularly heavily distributed under the organ capsule and scattered in the parenchyma, where they form a widespread three-dimensional network. Most of the pericapillary spaces were lined by CA-reactive cells. The reaction product, in the form of strongly electron-dark precipitates, was localized in the cytoplasmic matrix, whereas organelles, except for some mitochondrial intracristal spaces, were CA-negative. On the basis of localization and morphology of CA-positive cells, we conclude that these represent glial (interstitial) cells.