山羊蠕形螨扫描电镜观察

本文通过扫描电镜对寄生虫山羊体的山羊蠕形螨生活史各期颚体,足体和末体的超微结构观察,发现以下超微结构;一个圆锥状须乳突位于雌螨触须第２节背面;叶状背阳茎侧突和腹阳茎侧突竖立于阳茎同一基部,未受精雌螨船形阴门的一对瓣汇成纵线,雌螨交配后阴门半开,产卵后全部敞开,同时描述该螨的背基刺,锥状突,口下板,螯肢,基内叶,口孔,须爪和肛道等的超微结构,文中还讨论了锥状突,口下板,螯肢,基内叶,须爪和须乳突的功     

蠕形螨的检查方法

蠕形螨的检查方法蠕形螨（Ｄｅｍｏｄｅｘ）是一类微小的寄生性螨,其成虫呈蠕虫状,雌雄异体。根据曲魁遵所述,此虫大小的２５０μｍ×４０μｍ,虫体可分为头胸部及腹部两部分。该螨寄生于人体和其他哺乳动物皮内的皮脂腺和毛囊管内。寄生于人体的蠕形螨有毛囊形螨（Ｄ...     

人体蠕形螨简易保存的方法

<正> 人体蠕形螨的感染相当普遍,我国已有20多个省市进行了流行病学调查,各地检出率相差悬殊,甚至同一地区差异也较大。这虽与检查技术、方法、季节和受检者等情况有关,但据我们的观察,标本是否及时镜检,也能影响检出     

动物蠕形螨活动情况初步观察

蠕形螨属Demodex是一类小型螨,寄生于人、家畜、野生动物的皮肤毛囊和皮脂腺内,不仅影响人类健康,并能引起家畜和珍稀动物的蠕形螨病,严重时可以导致动物死亡,目前尚无理想的特效药物。近年来,国内外学者对蠕形螨的形态结构,致病力,感染途径以及诊疗方法等作了不少研究,但对动物蠕形螨的活动情     

人体蠕形螨爬行的观察

蠕形螨为一永久性寄生螨类,寄生于人体及家畜、哺乳类动物,种类繁多,目前报道的有120余种,常见的有40余种,寄生人体的有毛囊蠕形螨(Demodex folliculorum)、皮脂蠕形螨(Demodex brevis)、毛囊蠕形螨中华亚种(Demodex folliculorum sinensis)等,分别寄生于毛囊及皮脂腺内。可引起酒渣鼻、痤疮、眼睑炎等皮肤病,在人群中感染甚为普遍,同时也证实了其感染途径是通过直接接触而传播。为此,对蠕形螨活动力的研究是进一步探索其传病机制及防治的重要环节。人体蠕形螨在不同温度、湿度及酸碱度条件下生活能力的观察曾有报道(Spickett,1961;陈国定,1985)。但对其爬行规律及速度至今尚未见报道,为此我们对蠕形螨在不同温度条件下的爬行规律及速度作了系统的观察。今将结果报道如下。     

山羊蠕形螨双封整装片制作方法

山羊蠕形螨双封整装片制作方法赖为民,吴聪明四川农业大学雅安６２５０１４山羊蠕形螨病是一种常见的寄生虫病,对于养羊业具有极大的危害,特别是板皮遭受损伤,带来巨大经济损失。因此,在寄生虫课的教学上是很重要的一部份。为了便于教学和科研,制作长期保存的山羊蠕...     

大熊猫蠕形螨病组织病变的初步观察

大熊猫蠕形螨病的临床症状和危害已有记述〔1,2〕。本文通过一例病猫皮损活组织块,经石蜡包埋做成连续切片,HE染色,厚度为8μm,镜下见到表皮角质层增厚,棘层稍增厚,基层正常。毛囊漏斗部与皮脂腺导管都有不同程度的扩大,其内毛根脱落较多。同时,被许多蠕形螨碎片及完整的蠕形螨充塞。部分毛囊的上皮细胞有坏死脱落、核溶解及核碎裂现象;有的含虫毛囊周围的间质内有大量嗜中性粒细胞及嗜酸性粒细胞浸润;个别毛囊腔内充满大量嗜中性粒细胞及脓球;少数汗腺管内及其它结缔组织内也有炎性细胞浸润。组织内大熊猫蠕形螨主要寄生于毛囊上段,即漏斗…     

毛囊蠕形螨与皮脂蠕形螨基因组DNA的RAPD分析和序列比对

【目的】分析毛囊蠕形螨Demodex folliculorum（D.f.）和皮脂蠕形螨D. brevis（D.b.）基因组DNA的多态性, 对相关条带进行测序分析。【方法】采用改良小昆虫DNA提取法提取两种人体蠕形螨基因组DNA, 选择RAPD技术对其进行多态性分析, 将相关条带分别与pMD18-T载体连接, 克隆、测序后进行酶切鉴定和分析。【结果】毛囊蠕形螨共扩增15条带, 皮脂蠕形螨共扩增12条带;两种蠕形螨既有共有条带, 又有特异性条带;根据条带差异计算得到两种间的遗传距离为0.5556. 毛囊蠕形螨约800 bp处特异性条带测序结果显示, 序列片段长度为855 bp（GenBank登录号为FI277970）;特异性引物扩增和酶切鉴定均为毛囊蠕形螨所特有. 序列比对显示与阿糖胞苷DNA区域结合蛋白有46%的序列相似度。两种人体蠕形螨约300 bp处共有条带序列分析显示, 碱基序列均为341 bp（GenBank登录号分别为D.f. FI520176;D.b. FI520175）, 在第84和第165位点有2个碱基不同, 分别是A/G和C/T互换, 同源性高达99.4%. 但未发现有开放阅读框和相似度高的序列。 【结论】序列片段为855 bp的特异性条带为毛囊蠕形螨所特有;341 bp碱基序列为毛囊蠕形螨和皮脂蠕形螨所共有, 同源性高达99.4%. RAPD技术可用于两种人体蠕形螨基因组DNA的多态性分析和物种鉴定。     

几种环境因素对两种人体蠕形螨生活力的影响

本文就寄生人体的毛囊蠕形螨和皮脂蠕形螨在实验室条件下,对其在各种温度、湿度和酸碱度中的存活时间进行了观察。 在36℃,高湿的环境中,毛囊蠕形螨和皮脂蠕形螨成虫的存活时间分别达94和95小时。高温与干燥对其生存不利。两种蠕形螨对酸性环境的耐受力都强于碱性环境,特别皮脂蠕形螨更为突出。     

薄荷油体外抗蠕形螨效果及杀螨机制

采用透明胶带粘贴过夜法获取2种人体蠕形螨,随机分组,观察不同浓度的薄荷油的杀虫效果,并在MoticDMB5图像采集软件系统下拍摄虫体在薄荷油作用下的虫体死亡过程。结果表明,薄荷油有很强的体外杀灭2种人体蠕形螨的作用,尤其对皮脂蠕形螨的杀灭作用显著。随着药物浓度的增加及作用时间的延长,蠕形螨死亡率增高。12.5%、3.125%分别是薄荷油体外杀灭毛囊蠕形螨和皮脂蠕形螨的最适杀螨浓度。薄荷油作用于蠕形螨,可见虫体收缩扭动,活动加剧,消化管剧烈收缩,毛囊蠕形螨和皮脂蠕形螨体壁均有渗出物外溢。虫体表现为兴奋—痉挛—失水—松弛—死亡的典型症状。薄荷油对人体蠕形螨的杀灭机制主要通过神经毒性和直接毒杀作用,造成虫体破裂脱水而死亡。薄荷油是一种极具开发潜能的高效的天然杀螨药。     

A New Technique of Preparing Pollen for Scanning Electron Microscopy

A new technique which avoids the distortion usually present in acetolyzed pollen is outlined. The main steps include hydration in Aerosol-OT, ultrasonication in acetone: water, dehydration in ethanol, transfer to amyl acetate, and critical point drying. Experimental studies, in which pollen treated by the new technique is compared with untreated and with acetolyzed pollen, show much better expansion and more observable detail of exine and colpar structures in the pollen prepared by the new method. Damage to Euphorbiaceous grains, especially those with “crotonoid” ornamentation, is extensive using conventional acetolysis but is circumvented entirely by the critical point drying method. It is concluded that SEM and light microscope studies of pollen should include at least some preparations by a non-acetolytic method such as the present one in order to record an optimal amount of structural information.     

Correlation of Scanning and Transmission Electron Microscopy on the Same Tissue Sample

Tissue processed for scanning electron microscopy (SEM) in a critical point bomb utilizing Freon-13 showed excellent subsurface preservation when prepared for transmission electron microscopy (TEM). The critical point method is the only commercially available SEM preparation technique in which the quality of preservation will not limit microscopists in efforts to correlate SEM and TEM observations.     

A Method for Isolating and Preparing Silica Bodies in Grasses for Scanning Electron Microscopy

Silica bodies are discrete deposits of dehydrated silica within epidermal cells. To describe these bodies completely, surrounding organic and unsilicified material must be removed. Methods generally used for isolating and preparing silica bodies were unsuitable for most grass species. An effective method for studying grasses is described here. After ashing the plant tissue, the ash was repeatedly rinsed with HCl in a specialized multiple funnel manifold and collected on Nuclepore filters. In addition, the silica bodies were sonicated for a few minutes to remove any remaining mineral impurities. Compared to conventional procedures, this method has a number of advantages: unsilicified material and mineral impurities were removed effectively, smaller quantities of plant tissue could be used, and the loss of silica bodies was minimized.     

Scanning Electron Microscopy of Plant Roots

A glycol methacrylate infiltration and polymerization techniquewas used to prepare clover roots inoculated with Rhizobium forscanning reflection electron microscopy. Root hairs and epidermalcells were coated with many bacteria; some bacteria seemed tobe embedded in the wall surface. Root hair tips were often smoothbut some older root hair surfaces showed a fibrillar meshworkpattern. Small granules c. 0.18 µm diameter were presenton the root hair and epidermal cell walls. The root cap, someroot hairs, and some epidermal cells were covered by an amorphousfilm thought to be the mucigel.     

Scanning Electron Microscopy of Thermoplasma acidophilum

The scanning electron microscope was utilized to observe the morphology of the thermophilic, acidophilic mycoplasma, Thermoplasma acidophilum. Upon examination of the surface morphology, the size and shape of this unusual mycoplasma revealed its similarity to the other mycoplasmas that have been investigated.     

Scanning Electron Microscopy of Bacterial Colonies

A technique is described for observing bacterial colony growth. Bacillus cereus, B. subtilis, and B. cereus var. mycoides were grown on strips of dialysis membrane layered on nutrient agar. Microcolonies of the organisms on strips were fixed in Formalin vapor in situ; the strips then were removed from the agar and secured to scanning microscope specimen stubs without markedly disturbing the cellular arrangement. Scanning electron micrographs clearly depict morphology of individual cells, as well as the spatial orientation of cells within the colony. This technique is reproducible, adaptable, and simple.     

Transmission Electron Microscopy of Tissue Prepared for Scanning Electron Microscopy by Ethanol-Cryofracturing

Tissue processed for scanning electron microscopy by ethanol-cryofracturing combined with critical point drying was embedded and sectioned for transmission electron microscopy. Study of sections cut in a plane passing through the fracture edge indicated that preservation of cellular fine structure of fractured cells was excellent. Even at the most peripheral edge of the fracture there was no evidence that movement of cytoplasmic components occurred to distort the original structural organization of fractured cells. Lack of cytoplasmic detail in ethanol-cryofractographs has been due more to the nature of the fracturing of the tissue and to the obscuring effects of the metal coating than to structural deformation at the fracture edge or to limitations in resolving power of the scanning electron microscope used.     

Scanning Electron Microscopy of Ascospores of Schwanniomyces

Ascospores of the four recognized species of Schwanniomyces were examined by scanning electron microscopy. Spores of S. alluvius, S. castellii, and S. occidentalis, which were essentially identical, had abundant, long protuberances and wide, thin equatorial rings. The two known strains of S. persoonii differed from the other species as well as from each other. One strain had spores with a wide ring but only a few short protuberances; spores from the second strain were covered with craterlike depressions and had a narrow ring. Also examined were spores of Schwanniomyces hominis (=Saccharomyces rosei) which lacked a ring and were covered with short irregularly shaped protuberances, a finding consistent with the morphology of spores from other strains of S. rosei.