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排序方式: 共有68条查询结果,搜索用时 109 毫秒
1.
广谱肾综合征出血热病毒单克隆抗体的A35的生物学性状   总被引:1,自引:0,他引:1  
具有中和及血凝抑制活性的、能和世界各地分离到的肾综合征出血热病毒(HFRSV)发生反应的、广谱的单克隆抗体(McAb),对HFRSV的诊断和分子生物学研究都有重要意义。 本文着重比较了HFRSV McAbA5、A19、A25-1、A25-7和A35的生物学性状,并观察了对感染动物的实验治疗效果。  相似文献   
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In the present study, the antiviral properties of the bacteriocin subtilosin against Herpes simplex virus type 1 (HSV-1) and the safety and efficacy of a subtilosin-based nanofiber formulation were determined. High concentrations of subtilosin, the cyclical antimicrobial peptide produced by Bacillus amyloliquefaciens, were virucidal against HSV-1. Interestingly, at non-virucidal concentrations, subtilosin inhibited wild type HSV-1 and aciclovir-resistant mutants in a dose-dependent manner. Although the exact antiviral mechanism is not fully understood, time of addition experiments and western blot analysis suggest that subtilosin does not affect viral multiplication steps prior to protein synthesis. Poly(vinyl alcohol)-based subtilosin nanofibers with a width of 278 nm were produced by the electrospinning process. The retained antimicrobial activity of the subtilosin-based fibers was determined via an agar well diffusion assay. The loading capacity of the fibers was 2.4 mg subtilosin/g fiber, and loading efficiency was 31.6 %. Furthermore, the nanofibers with and without incorporated subtilosin were shown to be non-toxic to human epidermal tissues using an in vitro human tissue model. Taking together these results, subtilosin-based nanofibers should be further studied as a novel alternative method for treatment and/or control of HSV-1 infection.  相似文献   
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Stroke is the major cause of permanent disability and mortality in China. Apigenin-7-O-β-D-(-6''''-p-coumaroyl)-glucopyranoside (APG) is a glycoside subtype of apigenin and has the antioxidant activity; however, whether and how it plays a neuroprotective role following cerebral ischemia remains unknown. In present study, we adopted the oxygen glucose/reperfusion model in PC12 cells, bilateral common carotid artery occlusion model in C57B6 mice and middle cerebral artery occlusion model in SD rats to observe the therapeutic effects of APG on ischemic stroke. We also discussed the underlying mechanism. Treatment with 0.4 μg/ml or 0.8 μg/ml APG promoted cell viability and proliferation, reduced LDH release and apoptotic cell death levels in PC12 cells. Treatment with 50 mg/kg or 100 mg/kg APG at 30 minutes after reperfusion improved neurological outcomes in vivo, as demonstrated by elevation of neurological scores in both mice and rats. It also increased the number of survival neurons in mice and reduced infarct volume in rats. APG also increased the contents of Mn-SOD and the phosphorylation level of STAT3, elevated the antioxidant activity and reduced oxidative productions. These findings revealed a neuroprotective effect of APG, which possibly induced by the STAT3 phosphorylation-mediated Mn-SOD up-regulation.  相似文献   
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Objective

Gray matter loss in the limbic structures was found in recent onset post traumatic stress disorder (PTSD) patients. In the present study, we measured regional gray matter volume in trauma survivors to verify the hypothesis that stress may cause different regional gray matter loss in trauma survivors with and without recent onset PTSD.

Method

High resolution T1-weighted magnetic resonance imaging (MRI) were obtained from coal mine flood disaster survivors with (n = 10) and without (n = 10) recent onset PTSD and 20 no trauma exposed normal controls. The voxel-based morphometry (VBM) method was used to measure the regional gray matter volume in three groups, the correlations of PTSD symptom severities with the gray matter volume in trauma survivors were also analyzed by multiple regression.

Results

Compared with normal controls, recent onset PTSD patients had smaller gray matter volume in left dorsal anterior cingulate cortex (ACC), and non PTSD subjects had smaller gray matter volume in the right pulvinar and left pallidum. The gray matter volume of the trauma survivors correlated negatively with CAPS scores in the right frontal lobe, left anterior and middle cingulate cortex, bilateral cuneus cortex, right middle occipital lobe, while in the recent onset PTSD, the gray matter volume correlated negatively with CAPS scores in bilateral superior medial frontal lobe and right ACC.

Conclusion

The present study identified gray matter loss in different regions in recent onset PTSD and non PTSD after a single prolonged trauma exposure. The gray matter volume of left dorsal ACC associated with the development of PTSD, while the gray matter volume of right pulvinar and left pallidum associated with the response to the severe stress. The atrophy of the frontal and limbic cortices predicts the symptom severities of the PTSD.  相似文献   
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A wide range of phenotypic variation was observed among neopolyploids obtained from the diploid pear cultivar ‘Fertility’ by in vitro colchicine treatment. The variant plantlets had alterations in leaf characteristics. Neopolyploids had significantly different ratios of leaf length to leaf width compared to the diploid control. Shoot regeneration from leaf explants and rooting ability from in vitro shoots of neopolyploids was examined. Regeneration frequencies of shoots from leaf explants of seven of the nine neopolyploids were significantly decreased compared to the diploid control. The organogenic potential of neopolyploids was highly genotype-dependent for both shoots and roots. Tetraploid clone 4x − 4 failed to regenerate shoots from leaf explants and the pentaploid clone 5x − 2 failed to root from in vitro shoots. The results suggest that polyploidization caused the decrease in or loss of in vitro organogenic potential. Regenerated shoots derived from neopolyploids showed different phenotypes, depending on the ploidy of the donor plant.  相似文献   
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Background: Desmoplastic small round cell tumor (DSRCT) is an aggressive malignant tumor commonly found in young men; most occurs in the abdominal cavity. Here we conducted an in-depth analysis of a pregnant patient in our hospital and explored all the case information in the literature on small round cell carcinoma of women. Case presentation: A 27-year-old pregnant woman underwent tumor resection in our hospital at 29 weeks gestational age for a large progressive shoulder lump. The postoperative pathology showed that the mass was a DSRCT. Genetic testing found no fusion gene. At 36 weeks gestation, a painful mass was found in the breast and proved to be a metastatic focus of the desmoplastic small round cell tumor. Twenty days after a successful cesarean section at 40 weeks gestation, she received the VAC-IE chemotherapy regimen, successfully completed the first course, but when awaiting the next chemotherapy, unfortunately, the patient died during follow-up due to tumor recurrence and metastasis. Conclusion: The treatment of DSRCT in pregnant women requires a multidisciplinary consultation, and the treatment and examination during pregnancy are subject to many constraints, which may have a negative impact on the patient’s prognosis. Also, a review of the literature found that there is still no standard treatment protocol for DSRCT, and its prognosis in female patients is independent of age and tissue origin.  相似文献   
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Pear (Pyrus communis L.) is a nutrient-dense fruit with strong consumer demand and high commercial value. However, most cultivated pear varieties are often susceptible to diseases caused by fungi, bacteria, and viruses. The purpose of the present study was to establish an efficient genetic transformation and regeneration protocol, paving the way for genetic engineering of pear cultivars with enhanced disease resistance. Major factors that influence transformation and regeneration were examined and optimal conditions were established for efficient transformation from leaf explants of ‘Old Home’, a valuable pear interstem and rootstock. High transformation efficiency was achieved largely due to an improved infection/transformation induction strategy. Co-cultivation of Agrobacterium cells and leaf segments on a liquid induction medium yielded a fivefold increase in transformation frequency. Southern hybridization analysis revealed presence of reporter gene uidA in the genomic DNA samples from independent transgenic plants, confirming the integration of the transgene in recipient pear genomes. The stability of T-DNA integration was evaluated by the consistent presence of the Km selectable marker and the expression pattern of the introduced reporter gene uidA was analyzed by GUS histochemical assay.  相似文献   
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选择烟台海岸沙地抗沙埋强的单叶蔓荆(Vitex trifolia var.simplicifolia)为试材,在自然环境条件下根据单叶蔓荆匍匐茎长度进行了轻度(1/3茎长)、中度(2/3茎长)和重度半埋以及全埋处理。在沙埋20d后,测定了不同沙埋处理下匍匐茎各段上匍匐茎长度、枝条高度、不定根长度,以及可溶性糖、淀粉、纤维素含量,以探讨单叶蔓荆碳水化合物变化和转化在其耐沙埋中作用。结果显示,在轻度、中度半埋和全埋下单叶蔓荆匍匐茎长度均显著大于对照,被沙埋匍匐茎处有大量不定根生成;同时,可溶性糖和淀粉含量增高和纤维素含量下降,尤其是生长最快的匍匐茎顶部(如轻度半埋),茎中可溶性糖较低、淀粉增加最多,纤维素最低。但是被重度半埋和全埋的匍匐茎生长较少,茎中纤维素含量较多、淀粉含量较少。研究表明,沙埋是一种胁迫,它损伤叶片、扰乱碳水化合物代谢平衡。但它又是胁迫信号使植物产生适应性反应,它使未遭沙埋的匍匐茎顶端通过加速碳水化合物转化、分解纤维素、提高淀粉和可溶性糖含量,为顶端生长提供能量和营养,以加速匍匐茎快速生长摆脱沙埋。同时沙埋部位枝叶通过分解其纤维素,产生更多的可溶性糖和淀粉为匍匐茎不定根生长提供能量。因此,沙埋后匍匐茎内碳水化合物的转化是其快速生长和摆脱沙埋的能量来源而在其适应沙埋生长中起重要作用。单叶蔓荆对沙埋的适应性反应表现了其具有表型可塑性特性,该特性是其沙埋后维护匍匐茎顶部快速生长、不定根形成、碳水化合物转化以及具有较高抗沙埋能力的关键。  相似文献   
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