Pectoral fins of <Emphasis Type="Italic">Micropogonias furnieri</Emphasis>: a histochemical and ultrastructural study

The myotomal fibres of the pectoral fins of white croaker (Micropogonias furnieri) have been studied using histochemical techniques and transmission electron microscopy (TEM). Succinic dehydrogenase (SDH) for mitochondria, periodic acid Schiff (PAS) for glycogen, Sudan Black for lipids and myosin-adenosintriphosphatase (mATPase) pre-incubated at alkaline and acid pHs were used to visualize the contraction velocity. Three zones were determined: superficial (SZ), medium (MZ) and deep (DZ). Staining for SDH, PAS and Sudan Black was positive only in the SZ. The level of alkaline mATPase was the highest in fibres from the DZ, intermediate in the MZ and low in the SZ; at an acid pH, the reverse was obtained. Fibres from the SZ were small with large quantities of subsarcolemmal mitochondria, scarce intermyofibrilar mitochondria and a well-developed sarcoplasmic reticulum; the myofibrils displayed a polygonal distribution along the entire length of the fibre. Fibres in the MZ were larger than those in the SZ, the myofibrils were densely packed, mitochondria prevailed under the sarcolemma and the sarcoplasmic reticulum was not abundant. Fibres from the DZ were the largest, with ribbon-shaped myofibrils and scarce mitochondria. The intercellular space was abundant and nervous endings were frequently observed.     

鹤源大肠杆菌ESBLs基因型检测及其耐药性分析

采用K-B法检测40株鹤源大肠杆菌对17种抗菌药物的耐药性。根据耐药表型和超广谱β-内酰胺酶(ESBLs)的基因型流行情况,指导临床合理用药。结果表明:15株大肠杆菌为产ESBLs株。扩增出了与预期片段大小相符的TEM型、SHV型、CTX-M型、OXA型基因。产酶大肠杆菌耐药性明显比非产酶大肠杆菌严重。     

The Effect of the Hypertrophy Virus (MdSGHV) on the Ultrastructure of the Salivary Glands of Musca domestica (Diptera: Muscidae)

The salivary glands of insects play a key role in the replication cycle and vectoring of viral pathogens. Consequently, Musca domestica (L.) (Diptera: Muscidae) and the Salivary Gland Hypertrophy Virus (MdSGHV) serve as a model to study insect vectoring of viruses. A better understanding of the structural changes of the salivary glands by the virus will help obtain a better picture of the pathological impact the virus has on adult flies. The salivary glands are a primary route for viruses to enter a new host. As such, studying the viral effect on the salivary glands is particularly important and can provide insights for the development of strategies to control the transmission of vector-borne diseases, such as dengue, malaria, Zika, and chikungunya virus. Using scanning and transmission electron microscopic techniques, researchers have shown the effects of infection by MdSGHV on the salivary glands; however, the exact location where the infection was found is unclear. For this reason, this study did a close examination of the effects of the hypertrophy virus on the salivary glands to locate the specific sites of infection. Here, we report that hypertrophy is present mainly in the secretory region, while other regions appeared unaffected. Moreover, there is a disruption of the cuticular, chitinous lining that separates the secretory cells from the lumen of the internal duct, and the disturbance of this lining makes it possible for the virus to enter the lumen. Thus, we report that the chitinous lining acts as an exit barrier of the salivary gland.     

布氏白僵菌侵染杨干象幼虫体壁的扫描电镜及透射电镜观察

为了解布氏白僵菌对杨干象幼虫的侵染过程,利用扫描电镜与透射电镜研究了布氏白僵菌对杨干象幼虫体壁的侵染过程及超微结构变化。扫描电镜结果显示:接种12 h后,分生孢子成功附着于杨干象幼虫体壁不同区域,如气孔、感器周围与节间膜部位;接种24 h后,最早观察到布氏白僵菌以芽管或菌丝的形式穿透杨干象幼虫体壁,无附着孢产生;接种90、96 h后,由虫体内穿出的菌丝在虫体表面开始大量繁殖。透射电镜结果显示:菌丝在穿透过程中伴随着机械压力与组织溶解现象。接种第24 h时,菌丝穿入表皮;到第36 h时,大量菌丝侵入到皮细胞层中;到第48 h时,菌丝侵入皮细胞层后使皮细胞层发生变形,菌丝周围出现电子密度很低的光晕;到第60 h,表皮层与皮细胞层分离,菌丝周围的细胞器溶解,细胞核遭到破坏,菌丝周围出现絮状溶解物,这种现象在国内外均未见报道,证实了菌丝侵入杨干象幼虫体内过程中有酶的参与。到第72 h时,细胞内排列松弛变成空泡;第84 h时,菌丝段以无隔、1个隔或2个隔的方式在血腔内大量繁殖;到第96 h,菌丝从表皮中穿出。      

丙硫苯咪唑对人工感染鸭东方次睾吸虫作用的电镜研究

用镜检东方次睾吸虫囊蚴阳性的麦穗鱼饲喂雏鸭，连续１０天后，经口投服丙硫苯咪唑，驱虫１２小时后，剖检并收集虫体，扫描电镜和透射电镜检查。结果表明，口服丙硫苯咪唑后，扫描电镜下可见虫体皱缩，口、腹吸盘以及部分体壁凹陷，体棘脱落等损害。透射电镜下可见虫体肌层肌纤维数量增多，纵切面肌纤维呈波浪状外观，横切面可见肌纤维数量增多，同时还可见到空隙增多。卵黄腺细胞发育受抑制，Ⅰ期和Ⅲ期卵黄细胞增加，而Ⅱ卵黄细胞明显减少。     

人工感染鸭东方次睾吸虫病的病理组织学研究

本文应用光镜（LM）、扫描电镜（SEM）和透射电镜（TEM）对人工感染东方次睾吸虫家鸭的肝脏、胆囊进行了病理组织学研究。LM显示:肝实质细胞脂肪变性,胆小管广泛增生,肝间质结缔组织明显增生,嗜酸性细胞浸润。胆囊部分粘膜上皮脱落,粘膜下血管充、出血明显,炎性细胞浸润。SEM显示:胆囊壁部分粘膜脱落而显光滑。TEM显示:肝细胞滑面内质网明显增多,溶酶体和线粒体也有增加现象,溶酶体多集中在毛细胆管附近,部分细胞可见多量脂滴,有些肝细胞破溃,附近有炎性细胞浸润。肝血窦扩张,可见多量红细胞、嗜酸性颗粒白细胞和巨噬细胞。内皮细胞筛板部分增厚,内皮窗孔缩小。枯否氏细胞质内蠕虫样结构增多,吞噬能力加强。肝脏毛细胆管增生,部分可见胆栓位于管腔内,微绒毛变短,周围肝细胞外质膜增厚。     

Diamond and pore structure observed in wood charcoal

Conclusions Various carbon structures were observed in the wood charcoal sample: the well known pyrolytic graphite layers, onion-like particles, and diamond structure. It is suggested that wood charcoal carbonized at 700°C is a complex of various carbon structures. The pore structure was observed by electron microscopy, and it is supposed that the microstructure and pores are closely related. Further study of the microstructure during the carbonization process of charcoal is necessary to better understand the characteristic functions of wood charcoal for utilizing it as a source of carbon material.A summary of this study was presented at the 51st annual meeting of the Japan Wood Research Society, Tokyo, April 2001, and the 50th annual meeting of the Society of Materials Science, Osaka, May 2001     

对防腐处理前后遭细菌侵蚀的木材超微构造研究

用透射电镜观察了隧道式细菌在未经防腐剂处理的素材和处理过的木材[欧洲白桦(Betula pendula),欧洲赤松(Pinus silvestris)和挪威云杉(Picea abies)]中形成的腐朽现象,研究了细菌入侵木材细胞壁的过程。侵蚀是从木材细胞腔内开始,通过S_3层后,细菌在细胞壁的S_1层、S_2层及胞间层内移动并且分裂,引起木材细胞壁的降解。还观察了隧道式细菌、隧道的形态和超微结构。本研究表明具缘纹孔和单纹孔的纹孔膜比纹孔缘对细菌活动更有抗性。细菌可以侵入低浓度防腐剂(0.5％Tanalith NCA)处理过的木材,表明细菌具一定解毒能力。     

Salinity-Induced Ultrastructural Alterations in Leaf Cells of Rice (Oryza sativa L.)

Summary

High concentrations of NaCl significantly reduced the fresh and dry weights and lengths of roots and shoots. NaCl exhibited a more rapid effect in water culture than in soil culture. In both water and solid cultures, root growth was suppressed more severely than shoot growth. Electron microscopic studies revealed that NaCl caused swelling of thylakoids, accumulation of starch grains and lipid droplets, distortion of grana stacking, increase in the size and number of plastoglobuli and vesiculation of cellular membrane. Mitochondria became deficient in cristae, swelled and the matrix appeared pale in salt-treated plants as compared with control plants. Disappearance of nucleolus and nuclear chromatin and destruction of vascular tissues were occasionally observed in salt-treated plants.