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虫草在世界范围内广泛分布,具有多种生物活性及较高的食药用价值。为进一步丰富虫草真菌资源,本研究对从广东韶关丹霞山采集到的一份野生虫草样品进行了菌株的分离鉴定、生物活性评价和子实体的诱导培养。通过形态学和系统发育分析,将菌株ZYJ0835鉴定为布莱克韦尔虫草Cordyceps blackwelliae。利用5种不同的培养基进行液体发酵培养,发现该菌株的发酵上清液和菌丝体均具有抗氧化和纤溶活性。此外,该菌株还具有一定的抑菌活性。利用大米、小麦、柞蚕蛹3种培养基质,均成功诱导出子实体,并且人工培养的子实体也具有抗氧化和纤溶活性。本研究首次在中国境内报道布莱克韦尔虫草的分布,为进一步开发利用该虫草资源提供了理论依据。 相似文献
104.
Karthigayan Gunalan Xiaohong Gao Sally Shu Lin Yap Soak Kuan Lai Andrea Ravasio Sundar Ganesan Hoi Yeung Li Peter R. Preiser 《Cellular microbiology》2020,22(9)
Plasmodium falciparum responsible for the most virulent form of malaria invades human erythrocytes through multiple ligand‐receptor interactions. The P. falciparum reticulocyte binding protein homologues (PfRHs) are expressed at the apical end of merozoites and form interactions with distinct erythrocyte surface receptors that are important for invasion. Here using a range of monoclonal antibodies (mAbs) against different regions of PfRH1 we have investigated the role of PfRH processing during merozoite invasion. We show that PfRH1 gets differentially processed during merozoite maturation and invasion and provide evidence that the different PfRH1 processing products have distinct functions during invasion. Using in‐situ Proximity Ligation and FRET assays that allow probing of interactions at the nanometre level we show that a subset of PfRH1 products form close association with micronemal proteins Apical Membrane Antigen 1 (AMA1) in the moving junction suggesting a critical role in facilitating junction formation and active invasion. Our data provides evidence that time dependent processing of PfRH proteins is a mechanism by which the parasite is able to regulate distinct functional activities of these large processes. The identification of a specific close association with AMA1 in the junction now may also provide new avenues to target these interactions to prevent merozoite invasion. 相似文献
105.
借助计算机软件分析,设计出能特异性切割HPV11型644nt型644ntE2mNA的核酶。遵循Symons锤头状核酶结构和GUX剪切位点原则,靶序列存在32个剪切位点,通过计算机软件分析核酶的最佳剪切位点,并对底物及核酶的二级结构进行预测及进行相应基因生物学功能和基因同源性分析,筛选出2个锤头结构核酶。针对这两位点设计的核酶分别命名为RZ277和RZ3281。计算机分析显示,两核酶与底物切点两翼碱基形成锤头状结构,切点所在基因序列具有相对松驰的二级结构,位于该基因重要生物功能区内,是核酶的理想攻击区域,通过基因库检索,在已知人类基因中排除了与上述两核酶切点两翼碱基有基因同源性序列的可能性。并非所有的GUX位点(X:C、U、A)或CUX均可作为核酶的最佳剪切切割反应,为下一步将核酶用于细胞内和体内试验打下基础。 相似文献
106.
Differences in how writing systems represent language raise important questions about whether there could be a universal functional architecture for reading across languages. In order to study potential language differences in the neural networks that support reading skill, we collected fMRI data from readers of alphabetic (English) and morpho-syllabic (Chinese) writing systems during two reading tasks. In one, participants read short stories under conditions that approximate natural reading, and in the other, participants decided whether individual stimuli were real words or not. Prior work comparing these two writing systems has overwhelmingly used meta-linguistic tasks, generally supporting the conclusion that the reading system is organized differently for skilled readers of Chinese and English. We observed that language differences in the reading network were greatly dependent on task. In lexical decision, a pattern consistent with prior research was observed in which the Middle Frontal Gyrus (MFG) and right Fusiform Gyrus (rFFG) were more active for Chinese than for English, whereas the posterior temporal sulcus was more active for English than for Chinese. We found a very different pattern of language effects in a naturalistic reading paradigm, during which significant differences were only observed in visual regions not typically considered specific to the reading network, and the middle temporal gyrus, which is thought to be important for direct mapping of orthography to semantics. Indeed, in areas that are often discussed as supporting distinct cognitive or linguistic functions between the two languages, we observed interaction. Specifically, language differences were most pronounced in MFG and rFFG during the lexical decision task, whereas no language differences were observed in these areas during silent reading of text for comprehension. 相似文献
107.
中华眼镜蛇蛇毒经DEAE-Sepharose CL-6B。HPLC等多次柱层析分离出有抗补体及溶血活性的眼镜蛇蛇毒因子(Cobra venom factor,CVF),纯化后的CVF在聚丙烯酰胺凝胶电泳图谱上呈单一区带,分子量为225000—230000,等电点为6.20。用二硫苏糖醇还原经SDS-聚丙烯酰胺凝胶电泳得三类亚基,其分子量总和为237,000。 体外抗补体及溶血试验表明,CVF的作用是通过补体旁路途经使总补体活力下降。双向免疫电泳鉴定,发现CVF与人血清作用后,其中补体成分C_3分子的抗原性发生改变,则表明CVF的作用是通过激活补体成分C_3而发挥的。给豚鼠腹腔注射CVF(0.15ug/g体重)后,其血清总补体水平下降到正常值的3%以下,7天后回升,13天后恢复到正常水平。 单相免疫电泳表明,CVF与人补体C_3抗血清间无任何交叉免疫反应,但人血清与CVF抗血清间有微弱的免疫沉淀反应。另外,CVF的氨基酸组成与人补体C_3也较为相似。鉴定还表明眼镜蛇科中四种蛇毒与CVF抗血清有强烈的免疫沉淀反应,蝰蛇毒及海蛇毒也有免疫沉淀反应,但只有眼镜蛇毒具有抗补体活性。 相似文献
108.
目的探讨糖尿病早期肋间肌酶组织化学变化。方法应用酶组织化学方法观察糖尿病2周和4周大鼠肋间肌组织脱氢酶、水解酶和氧化酶活性变化。结果糖尿病2周大鼠肋间肌组织琥珀酸脱氢酶、谷氨酸脱氢酶和辅酶Ⅰ黄递酶活性较对照组增强,乳酸脱氢酶活性较对照组减弱,苹果酸脱氢酶、异柠檬酸脱氢酶、葡萄糖-6-磷酸脱氢酶、酸性磷酸酶、酸性-α-萘酸性酯酶和细胞色素氧化酶无变化。糖尿病4周大鼠肋间肌组织琥珀酸脱氢酶、苹果酸脱氢酶、谷氨酸脱氢酶、辅酶Ⅰ黄递酶、酸性磷酸酶和酸性-α-萘酸性酯酶活性较对照组增强,乳酸脱氢酶和细胞色素氧化酶活性较对照组减弱,异柠檬酸脱氢酶、葡萄糖-6-磷酸脱氢酶无变化。结论糖尿病2周大鼠肋间肌组织有氧氧化代谢能力增强,糖酵解能力减弱。糖尿病4周大鼠肋间肌组织有氧氧化能力增强、糖酵解能力减弱及能量代谢紊乱。在糖尿病早期呼吸肌存在代谢异常。 相似文献
109.
萨能奶山羊是著名的奶用山羊品种,波尔山羊则是世界著名的肉用山羊品种.为了研究波尔山羊体细胞在奶山羊卵母细胞中的去分化,我们将成年波尔山羊的颗粒细胞或耳皮肤成纤维细胞作为供核细胞(试验组),移入奶山羊中Ⅱ期的去核卵母细胞透明带下,经电融合和离子霉素与6-二甲基氨基嘌呤(6-DMAP)激活,直接移入同期发情奶山羊输卵管或经体内培养,将发育的重构胚移人同期发情羊子宫内.妊娠早期作B超诊断,确立妊娠的观察至足月.同时将奶山羊的35日龄胎儿成纤维细胞作供核细胞(对照组),按试验组同样方法处理,将重构胚直接移入同期发情的奶山羊输卵管内.结果试验组,波尔羊颗粒粒细胞与耳皮肤成纤维细胞的融合率分别为78.2%(115/147)、57.4%(116/202),重构胚卵裂率为85.8%(115/134),桑椹胚、囊胚的发育率38.8%(52/134),早期妊娠三头,分别于妊娠40、60、60日龄终止妊娠.对照组,融合率为89.5%(136/152),早期妊娠率为42.9%(6/14),四头受体足月分娩,产四头公羊羔,其中三头存活,一头分娩时死于肺不扩张,并体重过大,显示胎儿过大综合症.经基因型鉴定证实,这四头克隆羔羊均源于同一胎儿成纤维细胞系.以上结果表明,波尔羊体细胞核在奶山羊卵母细胞中能够去分化,并维持一定程度的发育. 相似文献
110.
Kong X Li X Cai Z Yang N Liu Y Shu J Pan L Zuo P 《Cellular and molecular neurobiology》2008,28(4):569-579
(1) Neurogenesis driven by neural stem cells (NSCs) is regulated by physiological and pathological factors. Melatonin (MT)
has profound neurotrophic and neuroprotective effects. Hence, we studied the role of MT in regulating the viability and differentiation
of NSCs derived from rat ventral midbrain. (2) NSCs were isolated from the rat ventral midbrain. The viability of NSCs was
determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-ulfophenyl)-2H-tetrazolium assay. The differentiation
of NSCs was examined by analyzing the expression of the neural markers, MT receptors, brain derived neurotropic factor (BDNF)
and glial cell line-derived neurotrophic factor (GDNF) with semi-quantitative RT-PCR, immunofluorescence cytochemistry, and
Western blot. (3) Our results showed that MT could promote the viability of NSCs. In addition, MT could significantly elevate
the mRNA and protein levels of tyroxine hydroxylase (TH), a marker of dopaminergic neurons, and decrease the expression of
the astrocytes maker glial fibrillary acidic protein (GFAP). MT also increased the production of BDNF and GDNF in the cultured
NSCs. Meanwhile, we first found that two subtypes of MT receptors, MT1 and MT2, were expressed in the ventral midbrain NSCs.
(4) These results demonstrated that MT could induce NSCs to differentiate into dopaminergic neurons and decrease astrocyte
production. These findings also suggest that MT could offer a beneficial tool in guiding directional differentiation of NSCs. 相似文献