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81.
Epstein-Barr virus (EBV) is a human herpesvirus that infects over 90% of the world's population that persists as a latent infection in various lymphoid and epithelial malignancies. The total number of EBV associated malignancies is estimated to exceed 200,000 new cancers per year. Current chemotherapeutic treatments of EBV-positive cancers include broad-spectrum cytotoxic drugs that ignore the EBV positive status of tumors and have limited safety and selectivity. In an effort to develop new and more efficacious molecules for inducing EBV reactivation, we have developed high-throughput screening assays to identify a class of small molecules (referred to as the C60 series) that efficiently activate the EBV lytic cycle in multiple latency types, including lymphoblastoid and nasopharyngeal carcinoma cell lines. In this paper we report our preliminary structure activity relationship studies and demonstrate reactivation of EBV in the SNU719 gastric carcinoma mouse model and the AGS-Akata gastric carcinoma mouse model.  相似文献   
82.
RNA has attracted considerable attention as a target for small molecules. However, methods to identify, study, and characterize suitable RNA targets have lagged behind strategies for protein targets. One approach that has received considerable attention for protein targets has been to utilize computational analysis to investigate ligandable “pockets” on proteins that are amenable to small molecule binding. These studies have shown that selected physical properties of pockets are important parameters that govern the ability of a structure to bind to small molecules. This work describes a similar analysis to study pockets on all RNAs in the Protein Data Bank (PDB). Using parameters such as buriedness, hydrophobicity, volume, and other properties, the set of all RNAs is analyzed and compared to all proteins. Considerable overlap is observed between the properties of pockets on RNAs and proteins. Thus, many RNAs are capable of populating conformations with pockets that are likely suitable for small molecule binding. Further, principal moment of inertia (PMI) calculations reveal that liganded RNAs exist in diverse structural space, much of which overlaps with protein structural space. Taken together, these results suggest that complex folded RNAs adopt unique structures with pockets that may represent viable opportunities for small molecule targeting.  相似文献   
83.
《Fungal biology》2019,123(8):618-624
This study examined the effect of climate change (CC) abiotic factors of temperature (20, 25, 30 °C), water activity (aw; 0.995, 0.98) and CO2 exposure (400, 1000 ppm) may have on (a) growth, (b) gene expression of biosynthetic toxin genes (Tri5, Tri6, Tri16), and (c) T-2/HT-2 toxins and associated metabolites by Fusarium langsethiae on oat-based media and in stored oats. Lag phases and growth were optimum at 25 °C with freely available water. This was significantly reduced at 30 °C, at 0.98 aw and 1000 ppm CO2 exposure. In oat-based media and stored oats, Tri5 gene expression was reduced in all conditions except 30 °C, 0.98 aw, elevated CO2 where there was a significant (5.3-fold) increase. The Tri6 and Tri16 genes were upregulated, especially in elevated CO2 conditions. Toxin production was higher at 25 °C than 30 °C. In stored oats, at 0.98 aw, elevated CO2 led to a significant increase (73-fold) increase in T2/HT-2 toxin, especially at 30 °C. Nine T-2 and HT-2 related metabolites were detected, including a new dehydro T-2 toxin (which correlated with T-2 production) and the conjugate, HT-2 toxin, glucuronide. This shows that CC factors may have a significant impact on growth and mycotoxin production by F. langsethiae.  相似文献   
84.
Genetic selection focused purely on production traits has proven very successful in improving the productive performance of livestock. However, heightened environmental and infectious disease challenges have raised the need to also improve the resilience of animals to such external stressors, as well as their efficiency in utilising available resources. A better understanding of the relationship between efficiency and production and health traits is needed to properly account for it in breeding programmes and to produce animals that can maintain high production performance in a range of environmental conditions with minimal environmental footprint. The aim of this study was to perform a meta-analysis of genetic parameters for production, efficiency and health traits in sheep and goats. The dataset comprised 963 estimates of heritability and 572 genetic correlations collated from 162 published studies. A threelevel meta-analysis model was fitted. Pooled heritability estimates for milk production traits ranged between 0.27 ± 0.03 and 0.48 ± 0.13 in dairy goats and between 0.21 ± 0.06 and 0.33 ± 0.07 in dairy sheep. In meat sheep, the heritability of efficiency traits ranged from 0.09 ± 0.02 (prolificacy) up to 0.32 ± 0.14 (residual feed intake). For health traits, pooled heritability was 0.07 ± 0.01 (faecal egg count) and 0.21 ± 0.01 (somatic cell score) in dairy goats and 0.14 ± 0.04 (faecal egg count) and 0.13 ± 0.02 (somatic cell score) in dairy sheep. In meat sheep, the heritability of disease resistance and survival traits ranged between 0.07 ± 0.02 (mastitis) and 0.50 ± 0.10 (breech strike). Pooled estimates of genetic correlations between resilience and efficiency traits in dairy goats were not significantly different from zero with the exception of somatic cell score and fat content (?0.19 ± 0.01). In dairy sheep, only the unfavourable genetic correlation between somatic cell score and protein content (0.12 ± 0.03) was statistically significant. In meat sheep only, the correlations between growth and faecal egg count (?0.28 ± 0.11) as well as between growth and dagginess (?0.33 ± 0.13) were statistically significant and favourable. Results of this meta-analysis provide evidence of genetic antagonism between production and health in dairy sheep and goats. This was not observed in meat sheep where most of the pooled estimates had high standard errors and were non-significant. Based on the obtained results, it seems feasible to simultaneously improve efficiency and health in addition to production by including the different types of traits in the breeding goal. However, a better understanding of potential trade-offs between these traits would be beneficial. Particularly, more studies focused on reproduction and resilience traits linked to the animal’s multi-trait response to challenges are required.  相似文献   
85.
Cloning and expression profiling of testis-expressed microRNAs   总被引:2,自引:0,他引:2  
Using a new small RNA cloning method, we identified 141 miRNAs from the mouse testis, of which 29 were novel. The 141 miRNAs were mapped onto all chromosomes except the Y chromosome and 2/3 of these miRNA genes exist as clusters. ∼ 70% of these miRNA genes were located in intronic or intergenic regions, whereas the remaining miRNAs were derived from exonic sequences. We further validated these cloned miRNAs by examining their expression in multiple mouse organs including developing testes and also in purified spermatogenic cells using semi-quantitative PCR analyses. Our expression profiling assays revealed that 60% of the testis-expressed miRNAs were ubiquitously expressed and the remaining are either preferentially (35%) or exclusively (5%) expressed in the testis. We also observed a lack of strand selection during testicular miRNA biogenesis, characterized by paired expression of both the 5′ strands and 3′ strands derived from the same precursor miRNAs. The present work identified numerous miRNAs preferentially or exclusively expressed in the testis, which would be interesting targets for further functional studies.  相似文献   
86.
Vietnam’s elephant population that has suffered severe declines during the past three decades is now believed to number 60–80 individuals in the wild. Cat Tien National Park is thought to be one of the key areas for the recovery of Vietnam’s elephants. We carried out a molecular genetic study of elephants in Cat Tien National Park and its adjoining areas with the objectives of estimating minimum population size, assessing genetic diversity, and obtaining insights into social organization. We obtained a minimum population size of 11 elephants based on a combination of unique nuclear microsatellite genotypes and mitochondrial haplotypes. While mitochondrial diversity based on a 600-base pair segment was high in this small sample of individuals, the six microsatellite loci examined showed low diversity and the signature of a recent population bottleneck. Along with nuclear genetic depauperation of Cat Tien’s elephants, we also report disruption of normal social organization, with different matrilines having coalesced into a single social group because of anthropogenic disturbance. The results emphasize the critical condition of this elephant population and the need for urgent conservation measures if this population is to be saved.  相似文献   
87.
Marine and freshwater ecosystems are increasingly at risk of large and cascading changes from multiple human activities (termed “regime shifts”), which can impact population productivity, resilience, and ecosystem structure. Pacific salmon exhibit persistent and large fluctuations in their population dynamics driven by combinations of intrinsic (e.g., density dependence) and extrinsic factors (e.g., ecosystem changes, species interactions). In recent years, many Pacific salmon have declined due to regime shifts but clear understanding of the processes driving these changes remains elusive. Here, we unpacked the role of density dependence, ecosystem trends, and stochasticity on productivity regimes for a community of five anadromous Pacific salmonids (Steelhead, Coho Salmon, Pink Salmon, Dolly Varden, and Coastal Cutthroat Trout) across a rich 40-year time-series. We used a Bayesian multivariate state-space model to examine whether productivity shifts had similarly occurred across the community and explored marine or freshwater changes associated with those shifts. Overall, we identified three productivity regimes: an early regime (1976–1990), a compensatory regime (1991–2009), and a declining regime (since 2010) where large declines were observed for Steelhead, Dolly Varden, and Cutthroat Trout, intermediate declines in Coho and no change in Pink Salmon. These regime changes were associated with multiple cumulative effects across the salmon life cycle. For example, increased seal densities and ocean competition were associated with lower adult marine survival in Steelhead. Watershed logging also intensified over the past 40 years and was associated with (all else equal) ≥97% declines in freshwater productivity for Steelhead, Cutthroat, and Coho. For Steelhead, marine and freshwater dynamics played approximately equal roles in explaining trends in total productivity. Collectively, these changing environments limited juvenile production and lowered future adult returns. These results reveal how changes in freshwater and marine environments can jointly shape population dynamics among ecological communities, like Pacific salmon, with cascading consequences to their resilience.  相似文献   
88.
摘要 目的:回顾性对比神经内镜手术与小骨窗开颅手术治疗高血压脑出血(HICH)疗效。方法:回顾性选取2018年7月~2021年3月期间在联勤保障部队第909医院治疗的83例HICH患者的临床资料。根据手术方式的不同,将患者分为A组(n=41)和B组(n=42),A组患者采用小骨窗开颅手术治疗,B组患者采用神经内镜手术治疗,对比两组围术期指标、并发症发生率、神经功能、生活能力、神经损伤指标及预后。结果:与A组相比, B组的手术时间、住院时间明显缩短,术中出血量减少,血肿清除率升高(P<0.05)。B组术后1周美国国立卫生研究院卒中量表(NIHSS)评分低于A组,Barthel指数评分高于A组(P<0.05)。B组术后1周神经元特异性烯醇化酶(NSE)、S100B 蛋白(S100B)、髓鞘碱性蛋白(MBP)、胶质纤维酸性蛋白(GFAP)水平低于A组(P<0.05)。B组的并发症发生率小于A组(P<0.05)。B组的预后良好率高于A组(P<0.05)。结论:神经内镜手术、小骨窗开颅手术治疗HICH均可获得较好的疗效,其中神经内镜手术在缩短手术时间、住院时间,减少术中出血量和并发症发生率,提高血肿清除率,减轻神经功能损伤,促进患者生活能力改善,改善患者预后方面的效果更为显著。  相似文献   
89.
目的探究化疗对小细胞肺癌(small cell lung cancer,SCLC)患者免疫功能的影响。方法选择2013年1月到2018年12月我院收治的95例小细胞肺癌患者为研究对象。患者第一周期、第二周期化疗前采用流式细胞术检测患者外周血淋巴细胞亚群水平,分别按照不同疗效及不同化疗方案对患者外周血淋巴细胞亚群进行比较。结果(1)化疗后,95例患者CD3+、CD4+、CD8+细胞平均值增加,CD19+、γδT细胞平均值减少,差异均有统计学意义(均P<0.05)。(2)化疗后,部分缓解组患者CD3+、CD8+细胞平均值增加,CD19+细胞减少,差异有统计学意义(均P<0.05);病情稳定组和病情进展组患者各细胞水平无显著变化(均P>0.05)。(3)依托泊苷联合顺铂(EP)方案组化疗后患者CD3+、CD8+细胞平均值增多,CD19+细胞减少,差异均有统计学意义(均P<0.05);伊立替康联合顺铂(IP)方案和依托泊苷联合卡铂(EC)方案组化疗后患者各细胞水平无显著变化(均P>0.05)。结论化疗可以调节小细胞肺癌患者的免疫功能,增强细胞免疫,降低体液免疫,其中EC方案对患者细胞免疫的增强作用较为显著。  相似文献   
90.
In chemical biology, the elucidation of chemical target is crucial for successful drug development. Because MHC class I molecules present peptides from intracellular damaged proteins, it might be possible to identify targets of a chemical by analyzing peptide sequences on MHC class I. Therefore, we treated cells with the autophagy-inducing chemical TMD-457 and identified the peptides presented on MHC class I. Many of the peptides were derived from molecules involved in ER trafficking and ER stress, which were confirmed by morphological and biochemical analyses. Therefore, our results demonstrate that analyzing MHC class I peptides is useful for the detection of chemical targets.  相似文献   
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