当前共找到 1086 篇文献分享,本页显示第 361 - 380 篇。
361.
李翛然
(2023-07-28 15:19):
#paper Role of neuroinflammation in neurodegeneration development doi:10.3892/mmr.2016.4948 这是一篇综述,陕西师范大学夏海滨/张伟锋教授团队,主要介绍炎症 神经退行病变之间的关联和联系,介绍了目前被生物信息及试验验证的一些总结,以及正在临床方面的进展。 总体来说,就是目前从国际上,越来越认可很多的严重疾病,比如神经退行病变,癌症的初始诱因都是炎症的持续发展,免疫系统的混乱以及细胞功能的变化。 从药物公司的角度来说,我有一个横向的很好的对比思路。 这个器官及细胞炎症的症候很能对应起中医的“湿气”,然而调控所谓的“湿气”其实就是把免疫系统调节正常。 免疫是一个直到目前为止,西方医学理论都没有完整的体系化解释清楚的一个大的系统性问题。 等待AI和更多的生物信息学介入,会让生物带来全新的革命。 至少这几年卖的最好的药 基本都是 单抗和细胞治疗,本质上都是免疫调节。
Abstract:
Neurodegeneration is a phenomenon that occurs in the central nervous system through the hallmarks associating the loss of neuronal structure and function. Neurodegeneration is observed after viral insult and mostly …
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Neurodegeneration is a phenomenon that occurs in the central nervous system through the hallmarks associating the loss of neuronal structure and function. Neurodegeneration is observed after viral insult and mostly in various so-called 'neurodegenerative diseases', generally observed in the elderly, such as Alzheimer's disease, multiple sclerosis, Parkinson's disease and amyotrophic lateral sclerosis that negatively affect mental and physical functioning. Causative agents of neurodegeneration have yet to be identified. However, recent data have identified the inflammatory process as being closely linked with multiple neurodegenerative pathways, which are associated with depression, a consequence of neurodegenerative disease. Accordingly, pro‑inflammatory cytokines are important in the pathophysiology of depression and dementia. These data suggest that the role of neuroinflammation in neurodegeneration must be fully elucidated, since pro‑inflammatory agents, which are the causative effects of neuroinflammation, occur widely, particularly in the elderly in whom inflammatory mechanisms are linked to the pathogenesis of functional and mental impairments. In this review, we investigated the role played by the inflammatory process in neurodegenerative diseases.
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362.
徐炳祥
(2023-07-26 17:11):
#paper doi: 10.1016/j.tem.2011.10.001. Trends in Endocrinology and Metabolism, 2012, Transcriptional networks and chromatin remodeling controlling adipogenesis。脂肪生成过程受一系列转录因子和表观遗传信号的控制,从而在时间上形成多波次的级联调控关系。此过程不仅是代谢研究的核心,也是表观遗传研究的重要载体。这篇旧文对脂肪生成过程中重要的转录因子的行为和调控关系,及其与其他表观信号的关系进行了梳理,并按照脂肪分化过程早期和晚期分别进行了系统性介绍。受限于时代,文中未涉及染色质空间构象和启动子-增强子相互作用的内容,但其主要观点至今仍有重要的参考价值。
Trends in endocrinology and metabolism: TEM,
2012-Feb.
DOI: 10.1016/j.tem.2011.10.001
PMID: 22079269
Abstract:
Adipocyte differentiation is tightly controlled by a transcriptional cascade, which directs the extensive reprogramming of gene expression required to convert fibroblast-like precursor cells into mature lipid-laden adipocytes. Recent global analyses …
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Adipocyte differentiation is tightly controlled by a transcriptional cascade, which directs the extensive reprogramming of gene expression required to convert fibroblast-like precursor cells into mature lipid-laden adipocytes. Recent global analyses of transcription factor binding and chromatin remodeling have revealed 'snapshots' of this cascade and the chromatin landscape at specific time-points of differentiation. These studies demonstrate that multiple adipogenic transcription factors co-occupy hotspots characterized by an open chromatin structure and specific epigenetic modifications. Such transcription factor hotspots are likely to represent key signaling nodes which integrate multiple adipogenic signals at specific chromatin sites, thereby facilitating coordinated action on gene expression.
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363.
颜林林
(2023-07-25 00:17):
#paper doi:10.1038/s41588-023-01452-5. Nature Genetics, 2023, Crosstalk between RNA m6A and DNA methylation regulates transposable element chromatin activation and cell fate in human pluripotent stem cells. 这篇文章开发了一种名为CARGO-BioID的方法,基于CRISPR技术 和 蛋白质邻位连接技术(Proximity Ligation Assay,PLA),能够抓取与基因组上特定转座元件(Transposable elements,TEs)区域序列相结合的蛋白,并通过质谱和ChIP-seq等实验,对这些蛋白进行鉴定和定量检测。文章以LTR7/HRV-H为目标,这是个灵长目特有的TE序列,通过上述技术方法,识别出与之结合的蛋白,其中包括 YTHDC2 和 TET1 这两个蛋白,前者是RNA m6A甲基化的读取器(reader),后者则是DNA 5mC甲基化的去甲基酶。随后,文章又利用一系列细胞实验,证实了这两个蛋白在该基因组区域上的生物学作用,包括相应的RNA甲基化与DNA甲基化之间的相互作用(crosstalk)、它们对TE活性的调控、以及对hPSC(人多能干细胞)分化命运的影响等。
Abstract:
Transposable elements (TEs) are parasitic DNA sequences accounting for over half of the human genome. Tight control of the repression and activation states of TEs is critical for genome integrity, …
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Transposable elements (TEs) are parasitic DNA sequences accounting for over half of the human genome. Tight control of the repression and activation states of TEs is critical for genome integrity, development, immunity and diseases, including cancer. However, precisely how this regulation is achieved remains unclear. Here we develop a targeted proteomic proximity labeling approach to capture TE-associated proteins in human embryonic stem cells (hESCs). We find that the RNA N-methyladenosine (mA) reader, YTHDC2, occupies genomic loci of the primate-specific TE, LTR7/HERV-H, specifically through its interaction with mA-modified HERV-H RNAs. Unexpectedly, YTHDC2 recruits the DNA 5-methylcytosine (5mC)-demethylase, TET1, to remove 5mC from LTR7/HERV-H and prevent epigenetic silencing. Functionally, the YTHDC2/LTR7 axis inhibits neural differentiation of hESCs. Our results reveal both an underappreciated crosstalk between RNA mA and DNA 5mC, the most abundant regulatory modifications of RNA and DNA in eukaryotes, and the fact that in hESCs this interplay controls TE activity and cell fate.
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364.
龙海晨
(2023-07-11 02:13):
#paper Sun M, Ji H, Xu N, Jiang P, Qu T, Li Y. Real-world data analysis of immune checkpoint inhibitors in stage III-IV adenocarcinoma and squamous cell carcinoma. BMC Cancer. 2022 Jul 13;22(1):762. doi: 10.1186/s12885-022-09843-3. PMID: 35831785; PMCID: PMC9277844. 这是一篇临床上回顾性研究肺癌的文章,主要研究对象:III-IV期肺腺癌和鳞状细胞癌患者。使用免疫检查点抑制剂immune checkpoint inhibitors (ICIs)方法治疗后的情况。对315名患者使用ICIs疗法,并对患者进行评估,发现,ICIs对肺癌患者有良好的疗效,显著提高了患者生存期中位数,也缓解了症状。从结果数据看,使用ICIs也存在不良反应。
Abstract:
Abstract Background This study was designed to investigate the clinical application, efficacy, and safety of immune checkpoint inhibitors (ICIs) in the treatment of lung cancer in the real world. Methods …
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Abstract Background This study was designed to investigate the clinical application, efficacy, and safety of immune checkpoint inhibitors (ICIs) in the treatment of lung cancer in the real world. Methods A retrospective, observational analysis was conducted on patients treated with ICIs in four tertiary hospitals in the region from January 2015 to March 2021, to evaluate the clinical efficacy of ICIs single-agent or combined chemotherapy and anti-vascular drugs in the first-line or second-line treatment of patients with lung cancer. Results Three hundred and fifteen patients were enrolled in this study. In patients with stage III-IV adenocarcinoma and Squamous cell carcinoma, the objective response rate (ORR) and disease control rate (DCR) were 35.5% (87/245) and 93.5% (229/245), respectively, the median progression-free survival (PFS) was 10.8 months, and the median overall survival (OS) was not reached. A total of 132 patients received ICIs as the first-line treatment, the median treatment cycle was 8 cycles (2–20 cycles), the short-term efficacy ORR was 38.6%, DCR was 93.9%, and the median PFS was 11.4 months. One hundred thirteen patients received ICIs treatment as second-line treatment, the median treatment cycle was five cycles (2–10 cycles), the short-term efficacy ORR was 31.9%, DCR was 92.9%, and the median PFS was 10.0 months. There were no statistically significant differences in ORR, DCR, or median PFS with ICIs as the first-line treatment compared with the second-line treatment(P > 0.05). The results of subgroup analysis showed that Eastern Cooperative Oncology Group performance status (ECOG PS), epidermal growth factor receptor (EGFR) mutation status, pathological type and number of treatment lines were not correlated with median PFS(P > 0.05). However, there were statistically significant differences in programmed death-ligand 1(PD-L1) expression, corticosteroid interference, and antibiotic (Abx) treatment among all groups (P < 0.05). In terms of safety, the overall incidence of adverse reactions in 315 patients was 62.5%, and the incidence of immune-related adverse events (irAEs) was 13.7%. Grade 1–2 and 3–4 incidence of adverse events were 34.9 and 27.65%, respectively. There were four patients who experienced fatal irAEs, two cases were liver damage leading to liver failure, one case was immune related pneumonia, and one case was immune related myocarditis. Conclusion In the real world, ICIs has a good effect on patients with lung cancer and significantly improves ORR and PFS.
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365.
AI 5.0.3
(2023-06-30 23:56):
#paper doi:10.1038/s41398-023-02471-w Both reactive and proactive control are deficient in children with ADHD and predictive of clinical symptoms.这篇文献介绍了ADHD儿童反应性控制和主动控制都相较于TD儿童出现了显著下降
Abstract:
Cognitive control deficits are a hallmark of attention deficit hyperactivity disorder (ADHD) in children. Theoretical models posit that cognitive control involves reactive and proactive control processes but their distinct roles …
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Cognitive control deficits are a hallmark of attention deficit hyperactivity disorder (ADHD) in children. Theoretical models posit that cognitive control involves reactive and proactive control processes but their distinct roles and inter-relations in ADHD are not known, and the contributions of proactive control remain vastly understudied. Here, we investigate the dynamic dual cognitive control mechanisms associated with both proactive and reactive control in 50 children with ADHD (16F/34M) and 30 typically developing (TD) children (14F/16M) aged 9-12 years across two different cognitive controls tasks using a within-subject design. We found that while TD children were capable of proactively adapting their response strategies, children with ADHD demonstrated significant deficits in implementing proactive control strategies associated with error monitoring and trial history. Children with ADHD also showed weaker reactive control than TD children, and this finding was replicated across tasks. Furthermore, while proactive and reactive control functions were correlated in TD children, such coordination between the cognitive control mechanisms was not present in children with ADHD. Finally, both reactive and proactive control functions were associated with behavioral problems in ADHD, and multi-dimensional features derived from the dynamic dual cognitive control framework predicted inattention and hyperactivity/impulsivity clinical symptoms. Our findings demonstrate that ADHD in children is characterized by deficits in both proactive and reactive control, and suggest that multi-componential cognitive control measures can serve as robust predictors of clinical symptoms.
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366.
彬
(2023-06-30 23:50):
#paper doi: 10.3168/jds.2022-22540. Effect of diets enriched in n-6 or n-3 fatty acid on dry matter intake, energy balance, oxidative stress, and milk fat profile of transition cows. 这篇文献表明增加日粮中n-3 PUFA的含量可以增加过渡期奶牛的DMI和产后的产奶量。与产后补充饲喂n-6 PUFA相比,补充饲喂n-3 PUFA能更有效地缓解产后净能量平衡。同时补充饲喂n-3 PUFA可以降低牛乳中n-6 PUFA/n-3 PUFA的比例,该作者推测这可能是生产有益于人体健康食物的一种策略。
Abstract:
The objective of this study was to determine the effect of dietary supplementation of n-3 polyunsaturated fatty acids (PUFA) and n-6 PUFA on dry matter intake (DMI), energy balance, oxidative …
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The objective of this study was to determine the effect of dietary supplementation of n-3 polyunsaturated fatty acids (PUFA) and n-6 PUFA on dry matter intake (DMI), energy balance, oxidative stress, and performance of transition cows. Forty-five multiparous Holstein dairy cows with similar parity, body weight (BW), body condition score (BCS), and milk yield were used in a completely randomized design during a 56-d experimental period including 28 d prepartum and 28 d postpartum. At 240 d of pregnancy, cows were randomly assigned to one of the 3 isoenergetic and isoprotein dietary treatments, including a control ration containing 1% hydrogenated fatty acid (CON), a ration with 8% extruded soybean (HN6, high n-6 PUFA source), and a ration with 3.5% extruded flaxseed (HN3; high n-3 PUFA source). The HN6 and HN3 diets had an n-6/n-3 ratio of 3.05:1 and 0.64:1 in prepartum cows and 8.16:1 and 1.59:1 in postpartum cows, respectively. During the prepartum period (3, 2, and 1 wk before calving), DMI, DMI per unit of BW, total net energy intake, and net energy balance were higher in the HN3 than in the CON and NH6 groups. During the postpartum period (2, 3, and 4 wk after calving), cows fed HN3 and HN6 diets both showed increasing DMI, DMI as a percentage of BW, and total net energy intake compared with those fed the CON diet. The BW of calves in the HN3 group was 12.91% higher than those in the CON group. Yield and nutrient composition of colostrum (first milking after calving) were not affected by HN6 or HN3 but milk yield from 1 to 4 wk of milking was significantly improved compared with CON. During the transition period, BW, BCS, and BCS changes were not affected. Cows fed the HN6 diet had a higher plasma NEFA concentration compared with the CON cows during the prepartum period. Feeding HN3 reduced the proportion of de novo fatty acids and increased the proportion of preformed long-chain fatty acids in regular milk. In addition, the n-3 PUFA-enriched diet reduced the n-6/n-3 PUFA ratio in milk. In conclusion, increasing the n-3 fatty acids concentration in the diet increased both DMI during the transition period and milk production after calving, and supplementing n-3 fatty acids was more effective in mitigating the net energy balance after calving.
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367.
Ricardo
(2023-06-30 23:49):
#paper Denoising Diffusion Probabilistic Models.
doi: https://doi.org/10.48550/arXiv.2006.11239 大名鼎鼎的DDPM模型,算法结构出奇的简单,分为前向加噪过程和反向去噪过程。前向加噪过程是通过在多个时间步里加小噪声,反向去噪过程则在每一个时间步上通过网络学习噪声分布去掉噪声。通过一长串的公式推导,其最终的损失函数相当的简单,就是个mse。看起来就像是很多个VAE叠加在一起。DDPM的一个缺点就是采样步长很长,通常需要1000步以上;而之后提出的DDIM模型将这个采样步长缩小到了50步左右,而这个效果是通过牺牲生成样本多样性实现的。DDIM模型通过一个叫做飘逸扩散方程的模型(这个模型在行为决策等研究中常常被采纳)来解释其原理。原本的DDPM模型其实只有漂移扩散方程中的扩散部分,而DDIM模型则加上了漂移的部分,可以将模型往数据采样密度较高的地方去靠近。
arXiv,
2020.
DOI: 10.48550/arXiv.2006.11239
Abstract:
We present high quality image synthesis results using diffusion probabilistic models, a class of latent variable models inspired by considerations from nonequilibrium thermodynamics. Our best results are obtained by training …
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We present high quality image synthesis results using diffusion probabilistic models, a class of latent variable models inspired by considerations from nonequilibrium thermodynamics. Our best results are obtained by training on a weighted variational bound designed according to a novel connection between diffusion probabilistic models and denoising score matching with Langevin dynamics, and our models naturally admit a progressive lossy decompression scheme that can be interpreted as a generalization of autoregressive decoding. On the unconditional CIFAR10 dataset, we obtain an Inception score of 9.46 and a state-of-the-art FID score of 3.17. On 256x256 LSUN, we obtain sample quality similar to ProgressiveGAN. Our implementation is available at this https URL
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368.
林海onrush
(2023-06-30 23:49):
#paper,doi:10.1017/fms.2015.2,A THEORY OF COMPLEXITY,CONDITION,AND ROUNDOFF,计算复杂性理论作为评判算法的重要标准,研究各种复杂性类的范围问题具有数学和工程意义,作者开发了一个理论的复杂性数值计算,考虑到输入数据的条件,并允许舍入的计算。Shub和Smale在R上的计算 (这又遵循了由Cook、Karp和Levin等人提出的经典、离散、复杂性理论)。特别专注于决策问题的复杂性类,不同版本的P,NP和EXP的多项式和非确定性多项式。及指数时间。作者证明了这些复杂性类之间的一些基本关系,并提供自然NP完全问题。
Forum of Mathematics, Sigma,
2015.
DOI: 10.1017/fms.2015.2
Abstract:
We develop a theory of complexity for numerical computations that takes into account the condition of the input data and allows for roundoff in the computations. We follow the lines …
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We develop a theory of complexity for numerical computations that takes into account the condition of the input data and allows for roundoff in the computations. We follow the lines of the theory developed by Blum, Shub and Smale for computations over $\mathbb{R}$ (which in turn followed those of the classical, discrete, complexity theory as laid down by Cook, Karp, and Levin, among others). In particular, we focus on complexity classes of decision problems and, paramount among them, on appropriate versions of the classes $\mathsf{P}$, $\mathsf{NP}$, and $\mathsf{EXP}$ of polynomial, nondeterministic polynomial, and exponential time, respectively. We prove some basic relationships between these complexity classes, and provide natural NP-complete problems.
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369.
小W
(2023-06-30 23:48):
#paper doi:https://doi.org/10.1016/j.cmet.2023.05.008 Ketogenic diet promotes tumor ferroptosis but induces relative corticosterone deficiency that accelerates cachexia 一项关于生酮饮食(KD)饿死肿瘤的研究。之前的研究(2022)指出生酮饮食的代谢产物β-羟丁酸(BHB,脂肪酸代谢后产生的酮体)可通过与细胞表面受体Hcar2结合,诱导转录调节因子Hopx表达增加,从而抑制肿瘤细胞增殖。本文则发现在产生IL-6相关(肝脏生酮损伤)的癌症小鼠模型,生酮饮食的抗癌作用与存活率(OS)不符合。生酮饮食延缓小鼠的肿瘤生长,但加速恶病质的进展,导致总体生存期缩短。作者通过代谢组学和转录组学数据,证明在肿瘤中,KD不仅通过营养剥夺,同时脂质过氧化增加,导致癌细胞的铁死亡。在宿主系统中KD增加了脂质氢过氧化物(looh)的产生,使GSH通路饱和,消耗NADPH储存,同时导致LPPs的积累,导致应激引起的食欲抑制因子GDF-15的升高。NADPH辅助因子的不足,导致下丘脑-垂体-肾上腺(HPA)轴缺陷,诱导相对低皮质酮血症,导致应激反应缺陷和癌症恶病质的早期发作。地塞米松(皮质类固醇)给药,降低了正常饮食喂养小鼠的PFS和OS,延长了KD喂养小鼠的PFS和OS。IL-6相关癌症小鼠OS:KD / 正常 + 地塞米松 < 正常 < KD + 地塞米松。IL-6相关癌症小鼠PFS:正常 + 地塞米松 < 正常 < KD / KD + 地塞米松。
Abstract:
Glucose dependency of cancer cells can be targeted with a high-fat, low-carbohydrate ketogenic diet (KD). However, in IL-6-producing cancers, suppression of the hepatic ketogenic potential hinders the utilization of KD …
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Glucose dependency of cancer cells can be targeted with a high-fat, low-carbohydrate ketogenic diet (KD). However, in IL-6-producing cancers, suppression of the hepatic ketogenic potential hinders the utilization of KD as energy for the organism. In IL-6-associated murine models of cancer cachexia, we describe delayed tumor growth but accelerated cachexia onset and shortened survival in mice fed KD. Mechanistically, this uncoupling is a consequence of the biochemical interaction of two NADPH-dependent pathways. Within the tumor, increased lipid peroxidation and, consequently, saturation of the glutathione (GSH) system lead to the ferroptotic death of cancer cells. Systemically, redox imbalance and NADPH depletion impair corticosterone biosynthesis. Administration of dexamethasone, a potent glucocorticoid, increases food intake, normalizes glucose levels and utilization of nutritional substrates, delays cachexia onset, and extends the survival of tumor-bearing mice fed KD while preserving reduced tumor growth. Our study emphasizes the need to investigate the effects of systemic interventions on both the tumor and the host to accurately assess therapeutic potential. These findings may be relevant to clinical research efforts that investigate nutritional interventions such as KD in patients with cancer.
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370.
小擎子
(2023-06-30 23:20):
#paper doi:10.1126/science.aba6527 Science, 2020, Designed protein logic to target cells with precise combinations of surface antigens 设计蛋白质逻辑,以靶向具有表面抗原精确组合的细胞。文献从头设计了协同定位依赖性蛋白质开关(Co-LOCKR),可执行“AND”、“OR”和“NOT”布尔逻辑运算。只有当满足所有条件时,这些开关才会通过构象变化激活,实现在复杂细胞群中以单细胞分辨率产生快速的、转录依赖的反应。使用“AND”门来重定向T细胞对表达两种表面抗原的肿瘤细胞的特异性,同时避免对单抗原细胞的脱靶识别,以及添加“NOT”或“OR”以避免或包括表达第三抗原的细胞。文章涉及蛋白质设计知识太多了,有点看不懂,但是这个设计是很有想象力很有意思的,可以实现只在特定细胞的细胞膜附近反应的效果。蛋白质设计的门槛现在降得很低,但就像David Baker说的,关键是你想设计什么样的蛋白。
Abstract:
Precise cell targeting is challenging because most mammalian cell types lack a single surface marker that distinguishes them from other cells. A solution would be to target cells using specific …
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Precise cell targeting is challenging because most mammalian cell types lack a single surface marker that distinguishes them from other cells. A solution would be to target cells using specific combinations of proteins present on their surfaces. In this study, we design colocalization-dependent protein switches (Co-LOCKR) that perform AND, OR, and NOT Boolean logic operations. These switches activate through a conformational change only when all conditions are met, generating rapid, transcription-independent responses at single-cell resolution within complex cell populations. We implement AND gates to redirect T cell specificity against tumor cells expressing two surface antigens while avoiding off-target recognition of single-antigen cells, and three-input switches that add NOT or OR logic to avoid or include cells expressing a third antigen. Thus, de novo designed proteins can perform computations on the surface of cells, integrating multiple distinct binding interactions into a single output.
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371.
张贝
(2023-06-30 23:14):
#paper DNA methylation-based classification of central nervous system tumours Nature. 2018 Mar 22;555(7697):469-474.doi:10.1038/nature26000
肿瘤的正确诊断对于后期治疗至关重要,然而在已知的近100多种中枢神经系统肿瘤 (central nervous system tumor,CNS tumor)中,相关标准化的诊断面临很大的挑战。为了高效、迅速的对CNS肿瘤进行分类,作者开发了一个机器学习模型,它可以对甲基化数据进行分类。开发出来的程序经过训练后,可以使用甲基化特征鉴定91种CNS肿瘤。训练集采用的参照数据来自约2800名癌症患者。作者在1104例已经经过人工检查的中枢神经系统肿瘤上进行了测试,发现有12%例存在误诊。该模型不仅可以提高诊断准确率,而且还可以鉴定出新型罕见肿瘤。为了让这种新方法得到广泛应用,作者生成了一款免费在线工具 (Molecular Neuropathology 2.0; http://www.kitz-heidelberg.de/molecular-diagnostics),可以在几分钟内分析上传的数据。自2016年12月上线以来,该工具已被使用逾4500次,用户可以选择分享他们的数据,以便进一步优化算法。作者总结表示,将甲基化特征与脑肿瘤自动分类器整合起来还可以为创造类似的肿瘤分类算法用于诊断其它癌症类型提供一个蓝图。
Abstract:
Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has …
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Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has been shown to be particularly challenging-with substantial inter-observer variability in the histopathological diagnosis of many tumour types. Here we present a comprehensive approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups, and demonstrate its application in a routine diagnostic setting. We show that the availability of this method may have a substantial impact on diagnostic precision compared to standard methods, resulting in a change of diagnosis in up to 12% of prospective cases. For broader accessibility, we have designed a free online classifier tool, the use of which does not require any additional onsite data processing. Our results provide a blueprint for the generation of machine-learning-based tumour classifiers across other cancer entities, with the potential to fundamentally transform tumour pathology.
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372.
钟鸣
(2023-06-30 22:31):
#paper doi:10.1093/molbev/msad102 Caecilian Genomes Reveal the Molecular Basis of Adaptation and Convergent Evolution of Limblessness in Snakes and Caecilians
这是一篇比较基因组阐释进化问题的论文,比较的是蚓螈与蛇的基因组的共同特征,因为二者趋同进化至无足。作者分析了4个内容:重复区域分析、基因家族分析、正选择基因分析、ZRS增强子损失分析。分析结果集中于2点,第一点是这两个物种的基因组的 69% 以上都是由重复区域组成,其中逆转录转座子最为丰富。第二个发现是蚓螈的ZRS基因的增强子区域发生了缺失,这个基因在蛇中发生了突变,且该突变基因导入小鼠后会产生蛇样突变。这组证据强烈暗示该基因与无足表型的关联。
Abstract:
We present genome sequences for the caecilians Geotrypetes seraphini (3.8 Gb) and Microcaecilia unicolor (4.7 Gb), representatives of a limbless, mostly soil-dwelling amphibian clade with reduced eyes, and unique putatively …
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We present genome sequences for the caecilians Geotrypetes seraphini (3.8 Gb) and Microcaecilia unicolor (4.7 Gb), representatives of a limbless, mostly soil-dwelling amphibian clade with reduced eyes, and unique putatively chemosensory tentacles. More than 69% of both genomes are composed of repeats, with retrotransposons being the most abundant. We identify 1,150 orthogroups that are unique to caecilians and enriched for functions in olfaction and detection of chemical signals. There are 379 orthogroups with signatures of positive selection on caecilian lineages with roles in organ development and morphogenesis, sensory perception, and immunity amongst others. We discover that caecilian genomes are missing the zone of polarizing activity regulatorysequence (ZRS) enhancer of Sonic Hedgehog which is also mutated in snakes. In vivo deletions have shown ZRS is required for limb development in mice, thus, revealing a shared molecular target implicated in the independent evolution of limblessness in snakes and caecilians.
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373.
白鸟
(2023-06-30 22:26):
#paper https://www.frontiersin.org/articles/10.3389/fimmu.2023.1147718/full. The immunomodulatory mechanisms for acupuncture practice.
缘起:昨天跟同事聊起,他得了一种比较奇怪的病-面肌炎,跟自身免疫疾病有关,医生给他开了抗病毒的药物,特别提到对不同的穴位用针灸进行治疗。我一直也觉得中医和免疫系统应该是想通的,需要科学的解释。所以,想找一篇针灸和免疫相关的文献看看。
文献中,提到针灸是一种安全有效的调节人体免疫系统的医疗实践。需要针灸基于与现代西医不同的系统,因此当前的研究重点是针灸的作用和相关的神经生物学机制。本文对针灸的免疫调节机制进行综述,系统整合现有研究成果,阐明针灸对先天性和适应性免疫反应的调节作用,以及针灸免疫调节神经解剖学机制,包括完整的自主反射途径。这对于针灸医学的普及具有重要意义。
比较惭愧的是,文章我还没细读。最近在读免疫书,希望能加深一些人体免疫系统如何具体运行的理解。
Abstract:
The system physiology approaches that emerge in western countries in recent years echo the holistic view of ancient Traditional Chinese Medicine (TCM) practices that deal with the root, rather than …
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The system physiology approaches that emerge in western countries in recent years echo the holistic view of ancient Traditional Chinese Medicine (TCM) practices that deal with the root, rather than only the symptoms of diseases. Particularly, TCM practices, including acupuncture, emphasize the mobilization of self-healing mechanisms to bring back body homeostasis. Acupuncture has been practiced for over two thousand years to modulate body physiology stimulation at specific body regions (acupoints). With the development of various research on acupuncture therapy, its regulatory effect on the immune system has been gradually recognized, especially on immunological diseases, including infectious and allergic diseases. In this study, we reviewed the immunomodulatory mechanism of acupuncture and systematically integrates existing research to respectively elucidate the modulatory mechanisms of acupuncture on the innate immune system, adaptive immune system, and well-known neuroanatomical mechanisms, including intact somatosensory-autonomic reflex pathway. With the advances made in recent systems physiology studies, we now have a great opportunity to gain insight into how acupuncture modulates immunity, and subsequently improves its efficacy.
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374.
半面阳光
(2023-06-30 22:13):
#paper DOI:https://doi.org/10.1093/bib/bbab380, Briefings in Bioinformatics, 2022, NiPTUNE: an automated pipeline for noninvasive prenatal testing in an accurate, integrative and flexible framework.这篇文章整合了一个完整的NIPT生物信息流程。文章测试了NIPT生信分析中QC、Fetal fraction估计、fetal gender判断等几个关键步骤的不同分析工具和方法,给出了一套分析效果较好的工具组合。
Abstract:
Noninvasive prenatal testing (NIPT) consists of determining fetal aneuploidies by quantifying copy number alteration from the sequencing of cell-free DNA (cfDNA) from maternal blood. Due to the presence of cfDNA …
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Noninvasive prenatal testing (NIPT) consists of determining fetal aneuploidies by quantifying copy number alteration from the sequencing of cell-free DNA (cfDNA) from maternal blood. Due to the presence of cfDNA of fetal origin in maternal blood, in silico approaches have been developed to accurately predict fetal aneuploidies. Although NIPT is becoming a new standard in prenatal screening of chromosomal abnormalities, there are no integrated pipelines available to allow rapid, accurate and standardized data analysis in any clinical setting. Several tools have been developed, however often optimized only for research purposes or requiring enormous amount of retrospective data, making hard their implementation in a clinical context. Furthermore, no guidelines have been provided on how to accomplish each step of the data analysis to achieve reliable results. Finally, there is no integrated pipeline to perform all steps of NIPT analysis. To address these needs, we tested several tools for performing NIPT data analysis. We provide extensive benchmark of tools performances but also guidelines for running them. We selected the best performing tools that we benchmarked and gathered them in a computational pipeline. NiPTUNE is an open source python package that includes methods for fetal fraction estimation, a novel method for accurate gender prediction, a principal component analysis based strategy for quality control and fetal aneuploidies prediction. NiPTUNE is constituted by seven modules allowing the user to run the entire pipeline or each module independently. Using two cohorts composed by 1439 samples with 31 confirmed aneuploidies, we demonstrated that NiPTUNE is a valuable resource for NIPT analysis.
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375.
muton
(2023-06-30 21:57):
# Paper: Doeller, C. F., Barry, C., & Burgess, N. (2010). Evidence for grid cells in a human memory network. Nature, 463(7281), 657–661. https://doi.org/10.1038/nature08704
自由运动大鼠内嗅皮层中的网格细胞提供了自我定位的显著周期性表征,这表明了非常特殊的计算机制。然而,网格细胞在人类中的存在及其在整个大脑中的分布是未知的。本研究表明,大鼠内嗅皮层定向调节的网格细胞的优先放电方向与网格对齐,并且快跑与慢跑相比,网格细胞放电的空间组织更为明显。由于网格细胞的一致性特征,作者预测了在更宏观的信号,也就是人类的功能性磁共振成像(fMRI)记录中也会发现网格细胞的相关证据。因此,作者模拟老鼠的觅食任务,让参与者探索虚拟现实环境,结果显示fMRI激活和适应在跑步方向上显示出由速度调节的六倍旋转对称的特性。这种信号在鼻内/丘下、顶叶后部和内侧、颞外侧和前额叶内侧的网络中都有发现。并且该效应在右内嗅皮层表现最为明显,方向信号在内嗅皮层间的相干性与空间记忆表现相关。本研究提示了将单细胞电生理学与功能磁共振成像在系统神经科学中结合的潜在可能。本研究结果为人类的网格细胞样表征提供了证据,并暗示在支持空间认知和自传体记忆的区域网络中存在一种特定类型神经表征。
Abstract:
Grid cells in the entorhinal cortex of freely moving rats provide a strikingly periodic representation of self-location which is indicative of very specific computational mechanisms. However, the existence of grid …
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Grid cells in the entorhinal cortex of freely moving rats provide a strikingly periodic representation of self-location which is indicative of very specific computational mechanisms. However, the existence of grid cells in humans and their distribution throughout the brain are unknown. Here we show that the preferred firing directions of directionally modulated grid cells in rat entorhinal cortex are aligned with the grids, and that the spatial organization of grid-cell firing is more strongly apparent at faster than slower running speeds. Because the grids are also aligned with each other, we predicted a macroscopic signal visible to functional magnetic resonance imaging (fMRI) in humans. We then looked for this signal as participants explored a virtual reality environment, mimicking the rats' foraging task: fMRI activation and adaptation showing a speed-modulated six-fold rotational symmetry in running direction. The signal was found in a network of entorhinal/subicular, posterior and medial parietal, lateral temporal and medial prefrontal areas. The effect was strongest in right entorhinal cortex, and the coherence of the directional signal across entorhinal cortex correlated with spatial memory performance. Our study illustrates the potential power of combining single-unit electrophysiology with fMRI in systems neuroscience. Our results provide evidence for grid-cell-like representations in humans, and implicate a specific type of neural representation in a network of regions which supports spatial cognition and also autobiographical memory.
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376.
大勇
(2023-06-30 21:35):
#paper Dmitrieva-Posocco, O., Wong, A.C., Lundgren, P. et al. β-Hydroxybutyrate suppresses colorectal cancer. Nature 605, 160–165 (2022). https://doi.org/10.1038/s41586-022-04649-6 主要是讲述生酮饮食对小鼠结肠癌的抑制作用及可能的机制探讨,整篇文献降解较为精简,细节可以在文章中继续探索,生酮饮食对脂质、糖类和蛋白的代谢都会造成影响,从而导致结肠癌生长的抑制,酮类中的β羟丁酸可以通过Hcar2基因诱导Hopx的表达升高,从而抑制结肠癌进展。在生酮饮食研究中,其实还有其他研究表明生酮饮食会造成肿瘤的进展而非抑制,并且生酮饮食可能还会加速衰老和增加心血管疾病的风险,因此若非药用,日常不适宜进行尝试,目前在临床中没有太多的验证,而对于遗传代谢病中糖代谢异常的患者,生酮饮食则可能是他们目前最为稳妥的饮食方式,因为糖类可能对他们来说反而是毒药。
Abstract:
Colorectal cancer (CRC) is among the most frequent forms of cancer, and new strategies for its prevention and therapy are urgently needed. Here we identify a metabolite signalling pathway that …
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Colorectal cancer (CRC) is among the most frequent forms of cancer, and new strategies for its prevention and therapy are urgently needed. Here we identify a metabolite signalling pathway that provides actionable insights towards this goal. We perform a dietary screen in autochthonous animal models of CRC and find that ketogenic diets exhibit a strong tumour-inhibitory effect. These properties of ketogenic diets are recapitulated by the ketone body β-hydroxybutyrate (BHB), which reduces the proliferation of colonic crypt cells and potently suppresses intestinal tumour growth. We find that BHB acts through the surface receptor Hcar2 and induces the transcriptional regulator Hopx, thereby altering gene expression and inhibiting cell proliferation. Cancer organoid assays and single-cell RNA sequencing of biopsies from patients with CRC provide evidence that elevated BHB levels and active HOPX are associated with reduced intestinal epithelial proliferation in humans. This study thus identifies a BHB-triggered pathway regulating intestinal tumorigenesis and indicates that oral or systemic interventions with a single metabolite may complement current prevention and treatment strategies for CRC.
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377.
笑对人生
(2023-06-30 21:33):
#paper doi: 10.1038/s41586-021-03894-5. Epub 2021 Sep 8. Bentham R, et al. Using DNA sequencing data to quantify T cell fraction and therapy response. Nature. 2021 Sep;597(7877):555-560. doi: 10.1038/s41586-021-03894-5. Epub 2021 Sep 8.
在V(D)J重排过程中,T细胞受体alpha链编码基因(TCRA或TRA,T cell receptor-alpha gene)通常会发生丢失(TREC,T cell receptor excision circle)。基于此,本研究针对肿瘤配对的全外显子组测序数据开发了一个名为T cell ExTRECT的T细胞比例估计工具。该工具的原理主要是通过检测TRA基因发生肿瘤体细胞拷贝数变化(RDR,read-depth ratio),进而直接定量T细胞的比例。局限性:不能区分发生新抗原反应的T细胞和检测克隆型(clonotype);只能应用于全外显子组测序,要求测序深度大于30x。
Abstract:
The immune microenvironment influences tumour evolution and can be both prognostic and predict response to immunotherapy. However, measurements of tumour infiltrating lymphocytes (TILs) are limited by a shortage of appropriate …
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The immune microenvironment influences tumour evolution and can be both prognostic and predict response to immunotherapy. However, measurements of tumour infiltrating lymphocytes (TILs) are limited by a shortage of appropriate data. Whole-exome sequencing (WES) of DNA is frequently performed to calculate tumour mutational burden and identify actionable mutations. Here we develop T cell exome TREC tool (T cell ExTRECT), a method for estimation of T cell fraction from WES samples using a signal from T cell receptor excision circle (TREC) loss during V(D)J recombination of the T cell receptor-α gene (TCRA (also known as TRA)). TCRA T cell fraction correlates with orthogonal TIL estimates and is agnostic to sample type. Blood TCRA T cell fraction is higher in females than in males and correlates with both tumour immune infiltrate and presence of bacterial sequencing reads. Tumour TCRA T cell fraction is prognostic in lung adenocarcinoma. Using a meta-analysis of tumours treated with immunotherapy, we show that tumour TCRA T cell fraction predicts immunotherapy response, providing value beyond measuring tumour mutational burden. Applying T cell ExTRECT to a multi-sample pan-cancer cohort reveals a high diversity of the degree of immune infiltration within tumours. Subclonal loss of 12q24.31-32, encompassing SPPL3, is associated with reduced TCRA T cell fraction. T cell ExTRECT provides a cost-effective technique to characterize immune infiltrate alongside somatic changes.
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378.
尹志
(2023-06-30 21:30):
#paper https://doi.org/10.1002/ange.202210001, Angewandte Chemie 134.40 (2022), A Carbon-Carbon Bond Cleavage-Based Prodrug Activation Strategy Applied to β-Lapachone for Cancer-Specific Targeting。基本过了一遍,特别有意思的工作。文章提出了一种新型的前药(prodrug)设计策略,利用C-C键断裂来生成父药(parent drug)。在文章中这个父药是β-Lapachone, 一种对胰腺癌和肺癌有靶向效果的药物分子。前药设计策略是靶向药设计的一种现代方法,它的思路是,很多药物直接服用或者使用对患者的毒性较高,因此治疗窗口就较小。而前药设计策略是,将父药包装成前药分子,然后通过前药分子的摄入进入体内,然后在到达靶点之后,通过某种方式,转变为父药,进而被激活,产生药物活性。这个过程降低了药物毒性的影响,延长了治疗窗口。传统上,前药激活的方式是通过断裂C-N/C-O键,但是很多可修饰基团没有C-N/C-O bond。作者的新策略是进行C-C bond的断裂,从而产生父药,从而产生药效。脑洞一下啊,今年初,张锋组的一篇工作,我之前在paper群有写,通过一种叫外胞质收缩注射系统的纳米机器,进行各种蛋白质负载的传递,我感觉和前药设计的思想很像啊,都是通过间接的方式,避开某种问题,实现最终效果,类似构建一套传递体系或者传递策略。这点上很值得借鉴。只能说,药物设计生物设计简直泰裤辣
Angewandte Chemie,
2022.
DOI: 10.1002/ange.202210001
Abstract:
Prodrugs are one of the most common strategies for the design of targeted anticancer agents. However, their application is often hampered by the modifiable groups available on parent drugs. Herein, …
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Prodrugs are one of the most common strategies for the design of targeted anticancer agents. However, their application is often hampered by the modifiable groups available on parent drugs. Herein, a carbon-carbon (C−C) bond cleavage-based prodrug activation strategy is reported, which was successfully used to design prodrugs of β-lapachone (β-lap), an ortho-quinone natural product without traditional modifiable groups for the construction of C−N/C−O bond cleavage-based prodrugs. The designed β-lap prodrug with a reactive oxygen species-specific trigger was quickly activated, releasing β-lap. It exerted anticancer efficacy via NAD(P)H:quinone oxidoreductase 1 (NQO1)-mediated futile redox cycling, resulting in potent cytotoxicity that was highly selective for NQO1-rich cancer cells over normal cells both in vitro and in vivo. This significantly amplified the therapeutic window of β-lap. This study provides a practical strategy for the design of prodrugs for parent drugs that do not contain traditional modifiable groups.
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379.
周周复始
(2023-06-30 20:39):
#paper 6-MONTH INFANT BRAIN MRI SEGMENTATION GUIDED BY 24-MONTH DATA USING CYCLE-CONSISTENT ADVERSARIAL NETWORKS.2020.doi: 10.1109/isbi45749.2020.9098515. 6个月左右白质和灰质之间的对比度极低,很难进行人工标注,训练标签的数量非常有限。因此,婴儿脑MRI的自动分割仍然具有一定的挑战性。但成人早期(如24个月)的图像的对比度相对较好,可以很容易地通过成熟的工具进行分割,例如FreeSurfer。因此,本文提出了一种利用24个月大的图像对6个月大的图像进行可靠的组织分割的方法。设计了一个3D-cycleGAN-Seg架构,通过在两个时间点之间转移外观来生成等强度相位的合成图像。为了保证6个月和24个月的图像组织分割的一致性,使用生成的分割的特征来指导生成器网络的训练。为了进一步提高合成图像的质量,提出了一种特征匹配损失,即计算真实图像和伪图像未配对分割特征之间的余弦距离。然后,利用转移的24个月的图像,在6个月的图像上联合训练分割模型。
Abstract:
Due to the extremely low intensity contrast between the white matter (WM) and the gray matter (GM) at around 6 months of age (the isointense phase), it is difficult for …
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Due to the extremely low intensity contrast between the white matter (WM) and the gray matter (GM) at around 6 months of age (the isointense phase), it is difficult for manual annotation, hence the number of training labels is highly limited. Consequently, it is still challenging to automatically segment isointense infant brain MRI. Meanwhile, the contrast of intensity images in the early adult phase, such as 24 months of age, is a relatively better, which can be easily segmented by the well-developed tools, e.g., FreeSurfer. Therefore, the question is how could we employ these high-contrast images (such as 24-month-old images) to guide the segmentation of 6-month-old images. Motivated by the above purpose, we propose a method to explore the 24-month-old images for a reliable tissue segmentation of 6-month-old images. Specifically, we design a 3D-cycleGAN-Seg architecture to generate synthetic images of the isointense phase by transferring appearances between the two time-points. To guarantee the tissue segmentation consistency between 6-month-old and 24-month-old images, we employ features from generated segmentations to guide the training of the generator network. To further improve the quality of synthetic images, we propose a feature matching loss that computes the cosine distance between unpaired segmentation features of the real and fake images. Then, the transferred of 24-month-old images is used to jointly train the segmentation model on the 6-month-old images. Experimental results demonstrate a superior performance of the proposed method compared with the existing deep learning-based methods.
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380.
哪有情可长
(2023-06-30 16:14):
#paper Characterization of novel loci controlling seed oil content in Brassica napus by marker metabolite-based multi-omics analysis,Genome biology, 19 June 2023, doi.org/10.1186/s13059-023-02984-z 文章利用广泛靶向代谢物分析共检测到2173种代谢物,对代谢物和油菜含油量进行相关性分析,最终鉴定到131个跟含油量高度相关的代谢物,并将代谢物作为含油量的代谢标志物。对131个含有代谢物进行全基因组关联分析,鉴定到446个mQTL位点,结合群体转录组关联分析,共鉴定到与含油量标志物显著关联的7316个基因,后面作者们有找到催化黄酮生物合成第一步反应的一个基因,对该基因进行后续验证。现在作物上数据整合的落脚点还得是找基因进行验证
Abstract:
BACKGROUND: Seed oil content is an important agronomic trait of Brassica napus (B. napus), and metabolites are considered as the bridge between genotype and phenotype for physical traits.RESULTS: Using a …
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BACKGROUND: Seed oil content is an important agronomic trait of Brassica napus (B. napus), and metabolites are considered as the bridge between genotype and phenotype for physical traits.RESULTS: Using a widely targeted metabolomics analysis in a natural population of 388 B. napus inbred lines, we quantify 2172 metabolites in mature seeds by liquid chromatography mass spectrometry, in which 131 marker metabolites are identified to be correlated with seed oil content. These metabolites are then selected for further metabolite genome-wide association study and metabolite transcriptome-wide association study. Combined with weighted correlation network analysis, we construct a triple relationship network, which includes 21,000 edges and 4384 nodes among metabolites, metabolite quantitative trait loci, genes, and co-expression modules. We validate the function of BnaA03.TT4, BnaC02.TT4, and BnaC05.UK, three candidate genes predicted by multi-omics analysis, which show significant impacts on seed oil content through regulating flavonoid metabolism in B. napus.CONCLUSIONS: This study demonstrates the advantage of utilizing marker metabolites integrated with multi-omics analysis to dissect the genetic basis of agronomic traits in crops.
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