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     

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。     

毛囊蠕形螨的发育形态观察和存活适温范围研究

采用挤压涂片法或透明胶纸粘贴法获取毛囊蠕形螨,在数码显微镜Motic DM-B5软件系统下进行动态观察、拍摄和测量;然后对离体蠕形螨按批随机分组,观察不同温度下虫体的存活时间和活动力。结果系统地展示了毛囊蠕形螨发育过程各个时期的动态照片,发现毛囊蠕形螨的前若虫期有足4对,若虫期具有活动能力。离体实验表明,毛囊蠕形螨耐低温而不耐高温;存活适温范围在8～30℃之间,发育适温范围在20～30℃之间,发育最适温度为25～26℃;0℃以下或37℃以上温度对蠕形螨生存不利,54℃为致死温度,58℃为有效灭螨温度。这一研究结果为蠕形螨的体外培养和防治工作提供了可靠的理论依据。     

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。     

蠕形螨扫描电镜样本的制备方法

本文对蠕形螨扫描电镜样本制备方法做了一定改进,结果制得的山羊蠕形螨扫描电镜样本观察效果显著优于原有方法,该改进方法特别适用于于结节脓疱型蠕形螨扫描电镜样本的制备。     

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。     

人体蠕形螨的DNA提取与随机引物PCR检测

【目的】探索人体毛囊蠕形螨和皮脂蠕形螨DNA的提取方法。【方法】采用液氮反复冻融研磨法破碎螨体细胞, 选用改良小昆虫DNA提取法、碱裂解法和试剂盒提取法, 分别提取冻存时间在5个月内和8~10个月的毛囊蠕形螨和皮脂蠕形螨基因组DNA, 并用随机引物PCR方法进行检测。【结果】蛋白核酸测定仪检测结果显示, 试剂盒法提取的DNA纯度较高、量较多, 明显优于改良小昆虫法和碱裂解法。随机引物扩增结果显示清晰的DNA指纹图谱, 两种人体蠕形螨DNA指纹具有明显差异。蠕形螨冻存时间影响DNA提取的量, 但对DNA提取的纯度和RAPD指纹图谱影响较小。不同DNA提取方法提取的同一种蠕形螨DNA指纹图谱基本相似, 试剂盒法和改良小昆虫法提取的DNA样本条带多而清晰, 碱裂解法提取的样本条带少而模糊。【结论】液氮反复冻融研磨法破碎蠕形螨细胞是有效的, 蠕形螨冻存时间不宜超过6个月, 试剂盒提取法是提取蠕形螨DNA的好方法。RAPD技术可以用于这两种人体蠕形螨DNA分子水平上的检测和分类。     

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…     

益肤净抗面部蠕形螨病及其合并症的效果观察

本文报道了中药制剂——“益肤净”抗人体面部蠕形螨感染及其合并症效果的实验结果。用透明胶带法进行计数检查。202人蠕形螨阳性检出者用药后显示,“益肤净”药剂安全可靠、无毒无不良反应。对102人,其中实验组(给药组)70人,用药后检查,阳性者只有1人(占1.4％);同时检查对照组32人,阳性者5人(占12.5)。两组阴转率有明显差异(P<0.05),表明“益肤净”有明显的抗蠕形螨感染作用。在202例蠕形螨感染中,有17例合并毛囊炎,用药三次后即完全治愈。表明“益肤净”对毛囊炎有抗炎消肿作用。在治疗25例合并痤疮患者中,有23例痊愈,2例好转,证明“益肤净”亦有较好地健美皮肤效能,可兼作美容化妆用品使用。     

硫磺皂对浙江大学生脸部蠕形螨防治效果分析

本文采取胶带法调查在校学生200人,面部螨虫感染人群占总人数48%,使用硫磺皂15天后,螨虫感染率下降有统计学意义,证明硫磺皂用于面部清洁对我浙江大学生面部螨虫的防治有效果。     

三种植物多糖肽的镇痛作用观察

三种植物多糖KA -PSP、AB -PSP、B1 -PSP灌胃给药 6天后 ,小鼠热板法实验发现AB -PSP呈现明显的镇痛作用 (P <0 .0 1 ) ,大鼠电刺激尾巴—嘶叫模型亦显示同样结果 ,其作用在给药后 1小时即有明显差异并持续至给药后 1 .5小时 (P <0 .0 0 1 )。     

Complete mitochondrial genomes of the human follicle mites Demodex brevis and D. folliculorum: novel gene arrangement,truncated tRNA genes,and ancient divergence between species

Background

Follicle mites of the genus Demodex are found on a wide diversity of mammals, including humans; surprisingly little is known, however, about the evolution of this association. Additional sequence information promises to facilitate studies of Demodex variation within and between host species. Here we report the complete mitochondrial genome sequences of two species of Demodex known to live on humans—Demodex brevis and D. folliculorum—which are the first such genomes available for any member of the genus. We analyzed these sequences to gain insight into the evolution of mitochondrial genomes within the Acariformes. We also used relaxed molecular clock analyses, based on alignments of mitochondrial proteins, to estimate the time of divergence between these two species.

Results

Both Demodex genomes shared a novel gene order that differs substantially from the ancestral chelicerate pattern, with transfer RNA (tRNA) genes apparently having moved much more often than other genes. Mitochondrial tRNA genes of both species were unusually short, with most of them unable to encode tRNAs that could fold into the canonical cloverleaf structure; indeed, several examples lacked both D- and T-arms. Finally, the high level of sequence divergence observed between these species suggests that these two lineages last shared a common ancestor no more recently than about 87 mya.

Conclusions

Among Acariformes, rearrangements involving tRNA genes tend to occur much more often than those involving other genes. The truncated tRNA genes observed in both Demodex species would seem to require the evolution of extensive tRNA editing capabilities and/or coevolved interacting factors. The molecular machinery necessary for these unusual tRNAs to function might provide an avenue for developing treatments of skin disorders caused by Demodex. The deep divergence time estimated between these two species sets a lower bound on the time that Demodex have been coevolving with their mammalian hosts, and supports the hypothesis that there was an early split within the genus Demodex into species that dwell in different skin microhabitats.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-1124) contains supplementary material, which is available to authorized users.     

Human Cartilage Tissue Fabrication Using Three-dimensional Inkjet Printing Technology

Bioprinting, which is based on thermal inkjet printing, is one of the most attractive enabling technologies in the field of tissue engineering and regenerative medicine. With digital control cells, scaffolds, and growth factors can be precisely deposited to the desired two-dimensional (2D) and three-dimensional (3D) locations rapidly. Therefore, this technology is an ideal approach to fabricate tissues mimicking their native anatomic structures. In order to engineer cartilage with native zonal organization, extracellular matrix composition (ECM), and mechanical properties, we developed a bioprinting platform using a commercial inkjet printer with simultaneous photopolymerization capable for 3D cartilage tissue engineering. Human chondrocytes suspended in poly(ethylene glycol) diacrylate (PEGDA) were printed for 3D neocartilage construction via layer-by-layer assembly. The printed cells were fixed at their original deposited positions, supported by the surrounding scaffold in simultaneous photopolymerization. The mechanical properties of the printed tissue were similar to the native cartilage. Compared to conventional tissue fabrication, which requires longer UV exposure, the viability of the printed cells with simultaneous photopolymerization was significantly higher. Printed neocartilage demonstrated excellent glycosaminoglycan (GAG) and collagen type II production, which was consistent with gene expression. Therefore, this platform is ideal for accurate cell distribution and arrangement for anatomic tissue engineering.     

3种便秘模型的比较研究

目的比较不同药物、同种药物不同动物及同种药物同种动物不同性别便秘模型的建造效果差异,探讨建模的最佳方案。方法 48只ICR小鼠(雌雄各半)随机分为6组(雌、雄正常对照组,雌、雄洛哌丁胺组,雌、雄硫糖铝组),每组动物数量相等,24只Wistar大鼠(雌雄各半)随机分为4组(雌、雄正常对照组,雌、雄洛哌丁胺组),每组数量相等,洛哌丁胺组1天2次洛哌丁胺灌胃给药,硫糖铝组1天1次灌胃给药。从动物体质量、饮水、进食、粪便含水量、口-肛传输时间及远端结肠组织学分析等指标进行造模效果评价。结果造模组与空白对照组在体重、粪便含水量及口-肛传输时间上有统计学差异(P<0.05),组织学造模组与空白对照组有差异;洛哌丁胺组与硫糖铝组差异不是很明显;雌性与雄性造模效果相比雌性更为显著。结论从造模效果、动物抵抗力、药物使用便捷程度等角度考虑,洛哌丁胺致雌性动物便秘模型较佳,而大鼠、小鼠的选择应根据具体药效实验而定。     

Cell Kinetic Study of Human Carcinomas Using Bromodeoxyuridine

Abstract. Cell kinetics in human malignant tumours were studied in vivo using bromodeoxyuridine (BrdU) and immunohistochemistry. BrdU was administered to twenty-four patients with gastric cancer at a dose of 1 g pre-operatively. Specimens were obtained during the operation, fixed in 70% ethanol and embedded in paraffin. BrdU-incorporating cells were detected by immunohistochemical staining using anti-BrdU monoclonal antibody. the labelling index (LI), determined by counting tumour cells microscopically, ranged from 4.0 to 41.4%. the LI was higher at the site of invasion than in the central area of the tumour, but no correlation was found between histological differentiation and LI. the LI of stage I gastric cancer was statistically lower than that of stage II, III and IV gastric cancers (P < 0.005). This technique, which is less cumbersome and time-consuming than using radioactive isotopes of thymidine, appears to be useful for studying cell kinetics of human malignant tumours.     

三种藻胆蛋白在复合累积LB膜中的能量传递

制备了R-藻红蛋白(R-PE)、C-藻蓝蛋白(C-PC)及变藻蓝蛋白(APC)的单组分累积LB膜及三组分复合累积LB膜. 吸收及荧光光谱测定表明三种蛋白的LB膜的光谱重叠性质与他们在水溶液中的性质相同. 结构测定表明, 三种蛋白在其LB膜中排列有序, 且由它们组装的复合累积LB膜结构类似于藻类植物中的藻胆体结构. 通过稳态荧光光谱及其光谱解叠, 观察到了三种蛋白在复合累积LB膜中的激发能量传递现象. 根据给体荧光峰的猝灭, 计算出在复合累积LB膜中从给体R-PE经C-PC到受体APC的能量传递效率为51%.