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目的明确妊娠期阴道白色念珠菌的基因型是否存在差异,了解不同基因分型方法的优劣。方法对628名妊娠妇女的阴道分泌物进行念珠菌培养和鉴定,以三种方法对比研究不同孕期白色念珠菌的基因型。结果妊娠期阴道念珠菌检出率为31.52%,白色念珠菌为最常见的菌种。INT引物PCR法可将126株白色念珠菌分为A、B、C三组,A组最为多见。EcoRⅠ酶切法可将119株白色念珠菌分为A、B、C三组和9个亚组,A—1亚组最常见。RAPD法扩增后,126株白色念珠菌共获得17种基因型,相似系数SAB=0.805±0.007,不同孕期的组内、组间SAB值均大于0.80。结论妊娠期阴道白色念珠菌具有显著的基因多态性,它们是由基因型非常相似的不同白色念珠菌。INT引物PCR法简便、快速,结果稳定、可靠,适于临床推广应用;RAPD法快速、简便、经济,分辨率高,适于临床和科研应用。 相似文献
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利用整体透明、石腊和薄切片方法对芸香科22属,40种和2变种植物叶分泌囊的形态结构和分
布进行了比较研究。成熟分泌囊都由鞘细胞和一层上皮细胞围绕圆形腔隙构成,上皮细胞扁平,细胞壁
薄、完整,故分泌囊属裂生方式发生。鞘细胞1～5层,不同种类的层数有变化,个别种缺乏。内层鞘细
胞为扁平的薄壁细胞,外层的细胞壁较厚。分泌囊的形态结构、着生位置和分布密度等在不同属或不同
种间存在一定差异。根据分泌囊在叶中的分布位置和形态结构特点,可将其划分为:叶缘齿缝分泌囊,
叶肉分泌囊和两者混合型。叶肉分泌囊又可分海绵组织分泌囊和栅栏组织分泌囊。在此基础上对该科各类型分泌囊的形态演化关系以及各亚科或各属间的亲缘关系进行了探讨。 相似文献
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强脉冲电场致细胞膜电穿孔的实验研究 总被引：2，自引：0，他引：2
采用肝癌细胞HePG2作为靶细胞,罗丹明偶联葡聚糖为荧光探针,荧光分光光度计作为检测设备,试验研究细胞膜电穿孔与电脉冲参数之间的关系.试验中发现随着电场强度或脉冲宽度的增加,样品荧光强度增加,细胞膜穿孔率相应增强;同时发现细胞膜电穿孔效应具有累积效应 相似文献
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什么叫生物膜?生物膜有何功能? 生物体主要包括动物、植物、微生物。除了病毒类病毒等以外,无论那种生物,其基本组成结构单位都是细胞。细胞作为一个独立结构单位,必然与外界微环境之间存在一定的屏障界线,被一层膜结构包裹,这就是细胞膜。在细胞内存在着多种细胞器,如线粒体、内质网、高尔基体等,它们基本上由膜组成或 相似文献
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目的：研究力竭运动模型建立的方法及SD大鼠力竭运动后血细胞形态结构的改变。方法：用平板运动的方法使SD大鼠做一次性力竭运动,并观察SD大鼠血涂片电镜照片和细胞计数。结果：平板运动能帮助建立力竭模型。力竭运动后SD大鼠血细胞形态以及红细胞、白细胞数量均有变化。结论：力竭运动可引起SD大鼠的造血器官机能下降,免疫能力下降。 相似文献
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目的:初步探讨有氧运动对白色脂肪棕色化的作用,为进一步研究肥胖的预防与治疗提供实验参考依据。方法:用高脂饲料喂养4周龄SD大鼠建立营养性肥胖模型。对造模成功的肥胖SD大鼠进行8周的有氧运动干预,测量其体重与体脂重量,并观察腹股沟白色脂肪组织HE染色结果。结果:运动组大鼠体重与附睾脂肪组织、肾周脂肪组织以及腹股沟脂肪组织的重量均低于肥胖组,且具有显著性差异;观察HE染色结果,运动组SD大鼠腹股沟白色脂肪组织中可见少量棕色脂肪细胞。结论:有氧运动可以降低营养性肥胖SD大鼠的体重和体脂水平,同时有助于白色脂肪棕色化,增加机体耗能,改善肥胖问题。 相似文献
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在细胞壁上有许多的为细胞生长而需要的特征,它们既为木材的识别提供了根据,又对木材加工利用有着关键的影响。细胞组成的木材,换而言之,细胞是作为木材构成的基本单位,木材细胞壁上结构特征的认知了解对木材检验工作有着重大的意义 相似文献
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聚-β-羟基丁酸(polyhydroxybutyric acid,PHB)是发现最早且研究最透彻的一种生物可降解塑料.莱茵衣藻(Chlamydomonas reinhardtii)素有"光合酵母"之称,是理想的转基因受体生物.通过转基因技术将PHB生物合成的关键酶基因导入莱茵衣藻,利用光合作用合成PHB,降低PHB的生产成本.从真养产碱杆菌(Alcaligenes eutrophus)分离出phbB和phbC基因,然后构建phbB和phbC基因的衣藻表达载体p105B124和pH105C124.通过"珠磨法"遗传转化技术共转化p105B124和pH105C124,获得了二价转基因衣藻.分子检测结果表明phbB和phbC基因均已整合到莱茵衣藻基因组中.随后进行结晶紫染色和显微镜观察转基因藻,发现二价转化子的核区和细胞膜附近分布有白色空泡;进一步的电子显微镜观察结果表明白色空泡是由细胞中合成的PHB聚集而成,电镜下观察到由PHB形成的明亮的圆形颗粒.光照(90μE/m2/s)条件下培养转基因藻,出现生长受抑制现象,这可能是由于PHB颗粒在藻细胞内随机分布,干扰了细胞正常的生命活动. 相似文献
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M. Bokaeian A. Nakhaee Bita Moodi A. Farhangi Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2010,25(2):182-187
The anti-candidial effect of garlic extract (Allium sativum L.) was investigated in normal and streptozotocin-induced diabetic
rats. Diabetes was induced after a single intraperitoneal injection of streptozotocin (60 mg/kg). Rats were divided into six
groups with fifteen rats in each group: (1) Normal control rats (2) Control rats + C. albicans (3) Control rats + garlic extract
+ C. albicans (4) Diabetic control rats (5) Diabetic rats + C. albicans (6) Diabetic rats + garlic extract + C. albicans.
The concerned groups were inoculated with C.albicans on the 15 th day. At the end of one month experiment, fasted rats were
killed by cervical decapitation. Blood was collected for estimation of glucose and C. albicans concentrations were estimated
in liver and kidneys homogenates. A significant increase was observed in serum glucose levels in diabetic rats. A loss of
bodyweight, polydipsia and polyphagia were observed in diabetic rats. Administration of alcoholic extract of garlic (0.25
g/kg body weight) reduced the hyperglycemia, polydipsia, polyphagia and associated weight loss of streptozotocin-treated rats.
Administration of garlic extract significantly reduced C. albicans concentrations in liver and kidneys homogenates in infected
control and diabetic rats. It is concluded that garlic extract improves candidia infection in diabetic rats. 相似文献
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We developed a new method for releasing viable cells from affinity-based microfluidic devices. The lumen of a microchannel with a U-shape and user-designed microstructures was coated with supported lipid bilayers functionalized by epithelial cell adhesion molecule antibodies to capture circulating epithelial cells of influx solution. After the capturing process, air foam was introduced into channels for releasing target cells and then carrying them to a small area of membrane. The results show that when the air foam is driven at linear velocity of 4.2 mm/s for more than 20 min or at linear velocity of 8.4 mm/s for more than 10 min, the cell releasing efficiency approaches 100%. This flow-induced shear stress is much less than the physiological level (15 dyn/cm2), which is necessary to maintain the intactness of released cells. Combining the design of microstructures of the microfluidic system, the cell recovery on the membrane exceeds 90%. Importantly, we demonstrate that the cells released by air foam are viable and could be cultured in vitro. This novel method for releasing cells could power the microfluidic platform for isolating and identifying circulating tumor cells. 相似文献
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氟他胺加睾丸切除治疗晚期前列腺癌22例报告 总被引：2，自引：0，他引：2
为探讨提高晚期前列腺癌的治疗效果，回顾性研究22例晚期前列腺癌的临床资料，运用氟他胺加睾丸切除治疗前列腺癌，其中C2期8例，D1期9例，D2期5例。结果：显效17例，有效3例，死亡2例，总有效率达90．9％。结果表明氟他胺是一个单纯抗雄激素的非类固醇化合物，对前列腺组织靶细胞膜上的雄激素受体有特异性阻断作用，能抑制雄激素依赖性肿瘤细胞生长，切除睾丸能降低雄激素水平，两者产生协同作用，提高疗效。 相似文献
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Axon path-finding plays an important role in normal and pathogenic brain development as well as in neurological regenerative medicine. In both scenarios, axonal growth is influenced by the microenvironment including the soluble molecules and contact-mediated signaling from guiding cells and cellular matrix. Microfluidic devices are a powerful tool for creating a microenvironment at the single cell level. In this paper, an asymmetrical-channel-based biochip, which can be later incorporated into microfluidic devices for neuronal network study, was developed to investigate geometric as well as supporting cell control of polarized axonal growth in forming a defined neuronal circuitry. A laser cell deposition system was used to place single cells, including neuron-glia pairs, into specific microwells of the device, enabling axonal growth without the influence of cytophilic∕phobic surface patterns. Phase microscopy showed that a novel "snag" channel structure influenced axonal growth in the intended direction 4:1 over the opposite direction. In heterotypic experiments, glial cell influence over the axonal growth path was observed with time-lapse microscopy. Thus, it is shown that single cell and heterotypic neuronal path-finding models can be developed in laser patterned biochips. 相似文献
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Organization of airway epithelium determines ciliary beat direction and coordination for proper mucociliary clearance. Fluidic shear stresses have the potential to influence ciliary organization. Here, an in vitro fluidic flow system was developed for inducing long-term airflow shear stresses on airway epithelium with a view to influencing epithelial organization. Our system consists of a fluidic device for cell culture, integrated into a humidified airflow circuit. The fluidic device has a modular design and is made from a combination of polystyrene and adhesive components incorporated into a 6-well filter membrane insert. We demonstrate the system operates within physiologically relevant shear and pressure ranges and estimate the shear stress exerted on the epithelial cell layer as a result of air flow using a computational model. For both the bronchial epithelial cell line BEAS2B and primary human tracheal airway epithelial cells, we demonstrate that cells remain viable within the device when exposed to airflow for 24 h and that normal differentiation and cilia formation occurs. Furthermore, we demonstrate the utility of our device for exploring the impact of exposing cells to airflow: our tool enables quantification of cytoskeletal organization, and is compatible with in situ bead assays to assess the orientation of cilia beating. 相似文献
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BackgroundThe exopolysaccharides (EPS) produced by yeast exhibit physico-chemical and rheological properties, which are useful in the production of food and in the cosmetic and pharmaceutical industries as well. The effect was investigated of selected carbon sources on the biosynthesis of EPS by Candida famata and Candida guilliermondii strains originally isolated from kefirs.ResultsThe biomass yields were dependent on carbon source (sucrose, maltose, lactose, glycerol, sorbitol) and ranged from 4.13 to 7.15 g/L. The highest biomass yield was reported for C. guilliermondii after cultivation on maltose. The maximum specific productivity of EPS during cultivation on maltose was 0.505 and 0.321 for C. guilliermondii and C. famata, respectively. The highest EPS yield was found for C. guilliermondii strain. The EPS produced under these conditions contained 65.4% and 61.5% carbohydrates, respectively. The specific growth rate (μ) of C. famata in medium containing EPS as a sole carbon source was 0.0068 h-1 and 0.0138 h-1 for C. guilliermondii strain.ConclusionsThe most preferred carbon source in the synthesis of EPS for both Candida strains was maltose, wherein C. guilliermondii strain showed the higher yield of EPS biosynthesis. The carbon source affected the chemical composition of the resulting EPS and the contribution of carbohydrate in the precipitated preparation of polymers was higher during supplementation of maltose as compared to sucrose. It was also found that the EPS can be a source of carbon for the producing strains. 相似文献
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BackgroundLiquid wax esters are widely used in cosmetic as well as pharmaceutical and other industries. The demand of organic and natural products is increasing nowadays. Coconut oil contains benefit fatty acids and has been mainly used for oil-based and moisturizer products. Liquid wax esters from coconut oil and unsaturated fatty alcohol can be synthesized by enzymatic reaction; and it is interesting for using as an alternative natural ingredient in these industries.ResultsOptimal condition for coconut oil based wax ester synthesis by immobilized lipase EQ3 was 10 U of enzyme, temperature at 30°C and molar ratio of coconut oil to oleyl alcohol at 1:3 (mol/mol) (0.33X) dissolved in isooctane for 12 h, while for Lipozyme RM IM optimal condition was 10 U of enzyme, temperature at 45°C and oil/alcohol molar ratio at 1:3 (0.33X) dissolved in isooctane for 3 h. Percentage of wax esters synthesized by both lipases reached more than 88%. Both immobilized lipases catalyzed high yield of wax esters within the 2nd batch; after that, the immobilized lipases showed reduced activity and synthesized < 60% of wax esters from the 3rd to 5th batch. The main composition of wax esters was ~ 48% oleyl laurate with 10% degradation at ~ 250°C.ConclusionsThe liquid wax ester synthesis by commercial Lipozyme RM IM had higher effect than immobilized lipase EQ3, but both catalysts were stable within 2 batches in the optimum condition. The characteristic properties of wax esters showed potential for use as components in cosmetics and skin care products.How to citeUngcharoenwiwat P, H-Kittikun A. Enzymatic synthesis of coconut oil based wax esters by immobilized lipase EQ3 and commercial lipozyme RMIM. Electron J Biotechnol 2020;47. https://doi.org/10.1016/j.ejbt.2020.06.005 相似文献
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热带假丝酵母（Candida tropicalis）是长碳链二元酸发酵生产中的常用菌种,而热带假丝酵母突变株HP-2-48是一株高产DC12的优良生产菌株。本文对十二碳二元酸的发酵进行了研究,考察了青霉素钠盐、尿素、丙烯酸、pH值对菌体生长、产酸的影响并对其作用机制进行了讨论,并据此建立了长碳链二元酸新的发酵工艺。 相似文献
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《Electronic Journal of Biotechnology》2014,17(1):34-38
BackgroundBiotechnological processes are costly, especially for the production of biosurfactants. The successful production of a biosurfactant is dependent on the development of processes using low cost raw materials. Considering the importance of the characteristics of a biosurfactant to facilitate its industrial application, the properties of the biosurfactant produced by Candida lipolytica through previously optimized medium have been established.ResultsThe yeast was grown for 72 h to determine the kinetics of growth and production. The surface tension of the cell-free broth was reduced from 55 to 25 mN/m. The yield of biosurfactant was 8.0 g/l with a CMC of 0.03%. The biosurfactant was characterized as an anionic lipopeptide composed of 50% protein, 20% lipids, and 8% of carbohydrates.ConclusionsThe isolated biosurfactant showed no toxicity against different vegetable seeds: Brassica oleracea, Solanum gilo and Lactuca sativa L. and the micro-crustacean Artemia salina. The properties of the biosurfactant produced suggest its potential application in industries that require the use of effective compounds at low cost. 相似文献
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Hasan Ebrahimi Shahmabadi Seyed Kazem Bagherpour Doun Seyed Ebrahim Alavi Mehri Mortazavi Zahra Saffari Maryam Farahnak Azim Akbarzadeh 《Indian journal of clinical biochemistry : IJCB》2014,29(3):357-361
Emulsion polymerization was used to synthesize poly butyl cyanoacrylate nanoparticles in presence of steric stabilizer dextran 70. Nanoparticles were characterized by particle size analysis, scanning electron microscopy and light microscopy. Polymerization factors affecting particle size and distribution such as dextran 70, polysorbate 80 (PS 80) and H+ concentration, polymerization time and temperature, and sonication were studied. Distinct concentrations of stabilizer were needed to produce proper nanoparticles. In this case, the appropriate value was 2 % of total volume. At pH 4 significant decrease in production efficiency demonstrated the substantial effect of H+ concentration on nanoparticles. Furthermore significant increases in particle size and distribution was observed at 50 °C compared to room temperature. 0.001 % (v/v) PS 80 represented notable influence on size and distribution. In addition, shaped nanoparticles were obtained by altering polymerization time from 5.5 h to 18 h. Finally, nanoparticle features were influenced by different factors. Appropriate manipulating of such factors can lead to obtaining desirable nanoparticles. 相似文献