共查询到20条相似文献，搜索用时 15 毫秒
1.
[目的]为提高滇重楼的繁殖效率。[方法]将滇重楼开花植株裂开花药的花粉轻轻涂抹载玻片上,分别用碘-碘化钾(I2!KI)染色法、氯化三苯四氮唑(TTC)染色法、醋酸洋红染色法和略有改动的荧光素二醋酸酯法对滇重楼花粉活力进行测定。[结果]氯化三苯基四氮唑染色法的染色率较低,仅为27.51%;醋酸洋红染色法和荧光素二醋酸酯法的染色率较高,分别为91.30%和90.55%,而且所测数据较为接近;碘-碘化钾染色法虽然能将花粉染上色,染色率为94.80%,但染上色的花粉包含退化的花粉和失活的花粉。[结论]醋酸洋红染色法和荧光素二醋酸酯染色法的染色率较高,能较好地区分出有活力的花粉和失活的花粉,而且能较为准确地反映滇重楼花粉的生活力。 相似文献
2.
Salivary gland lysates from the sand fly Lutzomyia longipalpis enhance Leishmania infectivity 总被引：21，自引：0，他引：21
Leishmaniasis is a parasitic disease transmitted by phlebotomine sand flies. The role of sand fly saliva in transmission of the disease was investigated by injecting mice with Leishmania major parasites in the presence of homogenized salivary glands from Lutzomyia longipalpis. This procedure resulted in cutaneous lesions of Leishmania major that were routinely five to ten times as large and contained as much as 5000 times as many parasites as controls. With inocula consisting of low numbers of Leishmania major, parasites were detected at the site of injection only when the inoculum also contained salivary gland material. This enhancing effect of sand fly salivary glands on cutaneous leishmaniasis occurred with as little as 10 percent of the contents of one salivary gland of one fly. Material obtained from other bloodsucking arthropods could not mediate the phenomenon. 相似文献
3.
马铃薯小孢子原生质体游离的影响因素 总被引：1，自引：1，他引：0
以马铃薯减数分裂四分体时期的小孢子为材料,研究了小孢子原生质体游离的主要影响因素。结果表明：用1 % 蜗牛酶+1.2 % 纤维素酶+0.5 % 半纤维素酶的混合酶液能大量游离出经低温预处理的马铃薯四分体小孢子原生质体,原生质体的最高产率达78.05 %;2-N吗啉乙烷磺酸 (MES) 对小孢子原生质体有一定的保护作用。0.1 % 的荧光增白剂鉴定脱壁完全,0.01 % 的FDA荧光检测表明原生质体具有生活力。 相似文献
4.
Ives A Ronet C Prevel F Ruzzante G Fuertes-Marraco S Schutz F Zangger H Revaz-Breton M Lye LF Hickerson SM Beverley SM Acha-Orbea H Launois P Fasel N Masina S 《Science (New York, N.Y.)》2011,331(6018):775-778
Mucocutaneous leishmaniasis is caused by infections with intracellular parasites of the Leishmania Viannia subgenus, including Leishmania guyanensis. The pathology develops after parasite dissemination to nasopharyngeal tissues, where destructive metastatic lesions form with chronic inflammation. Currently, the mechanisms involved in lesion development are poorly understood. Here we show that metastasizing parasites have a high Leishmania RNA virus-1 (LRV1) burden that is recognized by the host Toll-like receptor 3 (TLR3) to induce proinflammatory cytokines and chemokines. Paradoxically, these TLR3-mediated immune responses rendered mice more susceptible to infection, and the animals developed an increased footpad swelling and parasitemia. Thus, LRV1 in the metastasizing parasites subverted the host immune response to Leishmania and promoted parasite persistence. 相似文献
5.
6.
7.
In vivo imaging reveals an essential role for neutrophils in leishmaniasis transmitted by sand flies 总被引：1，自引：0，他引：1
Peters NC Egen JG Secundino N Debrabant A Kimblin N Kamhawi S Lawyer P Fay MP Germain RN Sacks D 《Science (New York, N.Y.)》2008,321(5891):970-974
Infection with the obligate intracellular protozoan Leishmania is thought to be initiated by direct parasitization of macrophages, but the early events following transmission to the skin by vector sand flies have been difficult to examine directly. Using dynamic intravital microscopy and flow cytometry, we observed a rapid and sustained neutrophilic infiltrate at localized sand fly bite sites. Invading neutrophils efficiently captured Leishmania major (L.m.) parasites early after sand fly transmission or needle inoculation, but phagocytosed L.m. remained viable and infected neutrophils efficiently initiated infection. Furthermore, neutrophil depletion reduced, rather than enhanced, the ability of parasites to establish productive infections. Thus, L.m. appears to have evolved to both evade and exploit the innate host response to sand fly bite in order to establish and promote disease. 相似文献
8.
Lethal effect of phenothiazine neuroleptics on the pathogenic protozoan Leishmania donovani 总被引：3，自引：0，他引：3
R D Pearson A A Manian J L Harcus D Hall E L Hewlett 《Science (New York, N.Y.)》1982,217(4557):369-371
Phenothiazine drugs, which are widely used for their antipsychotic, antianxiety, and antiemetic effects, have been found to have protozoacidal effects on the human pathogen Leishmania donovani. These compounds are lethal to both the extracellular stage of the organism, which is inoculated into humans by the sand fly, and the intracellular stage, which is found solely in human macrophages during established infection. 相似文献
9.
不结球白菜小孢子胚胎发生过程及发育途径研究 总被引：3，自引：0，他引：3
采用FDA荧光染色法对小孢子游离培养的发育过程进行了观察。结果表明:不结球白菜花粉母细胞减数分裂释放出的小孢子发育到单核靠边期及稍后时期染色最深、活力最强。多数游离小孢子培养经历的发育过程与合子胚相似,并且胚胎发育迅速,6～9 d产生大量球型胚,13 d开始出现子叶型胚胎。小孢子胚胎发育途径既有对称分裂并产生胚胎的途径(B途径),也有第1次不对称有丝分裂的方式;第1次不对称分裂后,既有营养细胞单独发育成胚的现象(A途径),也有营养细胞和生殖细胞共同发育成胚的现象(E途径),但未发现生殖细胞单独发育成胚的现象。 相似文献
10.
从10个具有不同镁碱化程度的采样点,采集土壤样品30个,测定土样pH、镁碱度、Mg2+/Ca2+、HCO3-+CO32-、钠碱度、有机碳、全氮、微生物生物量碳、荧光素二乙酸酯水解率、速效养分等指标。结果表明,镁碱化盐渍土有机碳、全氮、微生物生物量碳、微生物熵、荧光素二乙酸酯水解率、NH4+-N、NO3--N、速效磷等指标都与镁碱度和Mg2+/Ca2+显著负相关,表明镁碱化会造成土壤有机质含量降低、微生物群落变小、微生物活性下降、全量和速效养分含量偏低,镁碱化是导致土地生产力低下的原因之一。 相似文献
11.
12.
[目的]提高青阳参的坐果率。[方法]用解剖针小心将花粉块取下,并在解剖镜下将花粉块的膜剥开使其花粉粒散开置于载玻片上,用碘-碘化钾染色法(I2-KI)、氯化三苯四氮唑(TTC)染色法、醋酸洋红染色法和荧光素二醋酸酯(FDA)法对花粉生活力进行测定;花粉离体萌发法以整个花粉块为单位进行离体培养。[结果]:碘-碘化钾染色法(I2-KI)、氯化三苯四氮唑(TTC)染色法、醋酸洋红染色法、荧光素二醋酸酯(FDA)法的染色率均低于30.0%,而花粉离体萌发法测定的萌发率高达97.6%。[结论]花粉离体萌发法能对青阳参的花粉生活力进行有效的测定。 相似文献
13.
Despite the fact that Leishmania are transmitted exclusively by sand flies, none of the experimental models of leishmaniasis have established infection via sand fly bites. Here we describe a reproducible murine model of Leishmania major infection transmitted by Phlebotomus papatasi. Prior exposure of mice to bites of uninfected sand flies conferred powerful protection against Leishmania major that was associated with a strong delayed-type hypersensitivity response and with interferon-gamma production at the site of parasite delivery. These results have important implications for the epidemiology of cutaneous leishmaniasis and suggest a vaccination strategy against this and possibly other vector-borne diseases. 相似文献
14.
A Mukhopadhyay G Chaudhuri S K Arora S Sehgal S K Basu 《Science (New York, N.Y.)》1989,244(4905):705-707
Methotrexate coupled to maleylated bovine serum albumin was taken up efficiently through the "scavenger" receptors present on macrophages and led to selective killing of intracellular Leishmania mexicana amazonensis amastigotes in cultured hamster peritoneal macrophages. The drug conjugate was nearly 100 times as effective as free methotrexate in eliminating the intracellular parasites. Furthermore, in a model of experimental cutaneous leishmaniasis in hamsters, the drug conjugate brought about more than 90% reduction in the size of footpad lesions within 11 days. In contrast, the free drug at a similar concentration did not significantly affect lesion size. These studies demonstrate the potential of receptor-mediated drug delivery in the therapy of macrophage-associated diseases. 相似文献
15.
复合防腐剂在红肠保鲜中的应用 总被引：7，自引：0，他引：7
以哈尔滨红肠作为原料,研究在红肠中添加Nisin为主的复合防腐剂,提高其产品的保质期。复合防腐剂选用Nisin与山梨酸钾、双乙酸钠、EDTA二钠进行搭配,在(25±1)℃的条件下贮藏,每2天对细菌总数、pH、色差值及感官指标进行测定,并与市售的复合型防腐剂进行比较效果,找出最佳的防腐剂组合。结果表明,添加Nisin为主的复合防腐剂可显著降低细菌总数,并延长产品保质期,最佳添加量为Nisin 0.025%、山梨酸钾0.025%、双乙酸钠0.15%、EDTA二钠0.01%。 相似文献
16.
17.
Karyotype analysis of Leishmania species and its use in classification and clinical diagnosis 总被引：15，自引：0，他引：15
S H Giannini M Schittini J S Keithly P W Warburton C R Cantor L H Van der Ploeg 《Science (New York, N.Y.)》1986,232(4751):762-765
Chromosomes of four species of Leishmania represented by ten different geographic isolates were analyzed by pulsed field gradient gel electrophoresis (PFG) to assess chromosome stability in these parasitic protozoans. Among different geographic isolates of the same subspecies, more than two-thirds of chromosomes had similar sizes, ethidium bromide staining intensities, and locations of alpha,beta-tubulin genes. However, among New World Leishmania, members of different species or subspecies have fewer than one-third of their chromosomes in common. Therefore, PFG karyotypes of Leishmania exhibit intraspecific variability similar to that reported for other parasitic protozoans. The greater similarities of the karyotypes of members of the same Leishmania subspecies may indicate that they represent valid taxa. These similarities also allowed the use of PFG in clinical diagnosis for rapid and accurate typing of patient isolates. 相似文献
18.
Preparation of sarcolemmal membrane from myocardial tissue culture monolayer by high-velocity gas dissection 总被引：1，自引：0，他引：1
A high-velocity stream of nitrogen is used to simultaneously disrupt myocardial cells in monolayer culture and fractionate their sarcolemmal membranes. The membranes show a high degree of ultrastructural and enzymatic purity, with less than 1 percent intracellular residuum. They are produced in less than 1 second and remain as tightly adherent sheets on the surface on which the cells were grown. The cells are exposed to no agent other than nitrogen gas during the preparative procedure. 相似文献
19.
利用6种常用花粉活力测定方法对柱花草花粉活力进行测定,并筛选出各方法的最佳配方。结果表明:以离体萌发法为最佳,最适培养基:10%蔗糖、10%PEG-6000(聚乙二醇)、0.01%H3BO3、0.03%CaCl2.2H2O、0.01%KNO3,pH 6.5,柱花草花粉在该培养基上30℃条件下培养10 min,萌发率可达84.03%。0.5%I2+1.5%KI的碘-碘化钾染色效果好,色差明显,较离体萌发法测定值偏高,但差异不显著,可选作简单快速测定法;FDA(荧光素二醋酸脂)染色法、醋酸洋红染色法、无机酸法、TTC(2,3,5-氯代三苯基四氮唑)法均不适合柱花草花粉活力的检测。 相似文献
20.
为探讨猪粪炭对茶园土壤的改良作用,通过35 d的好气密闭培养实验,研究猪粪炭施加对茶园土壤的硝化过程、温室气体N2O排放及土壤微生物酶活性的影响。结果表明：施加猪粪炭可以改善茶园土壤的酸性环境,显著提高土壤pH,使其更适宜茶树的生长;茶树是典型的喜铵厌硝植物,较高的硝铵比不利于茶树的生长,低、中量猪粪炭施加显著增加土壤pH,并未促进茶园土壤的硝化作用,且显著降低土壤N2O累积排放量高达41.2%~58.7%;高量猪粪炭施加显著增加茶园土壤净硝化速率,降低N2O累积排放量62.4%;猪粪炭施加显著提高土壤FDA水解酶、脲酶及脱氢酶活性。研究表明,适量猪粪炭的添加可以改善茶园土壤的酸碱环境和微生物活性,促进土壤的生物化学反应和土壤养分元素的循环,从而提高土壤养分的可利用性和土壤质量。 相似文献