• 主题
高级搜索  >
历史搜索 清空历史

您现在的位置：首页>美国卫生研究院文献>Acta Naturae

期刊信息

  • 期刊名称：

    -

  • 刊频： Quarterly
  • NLM标题： Acta Naturae
  • iso缩写： -
  • ISSN： -

年度选择

更多>>

  • 排序：
  • 显示：
  • 每页：
全选（0）
<1/20>
共508条结果
  • 1.

    【2hr】Application of Polyhydroxyalkanoates in Medicine and the Biological Activity of Natural Poly(3-Hydroxybutyrate)

    包量

    机译 聚羟基链烷酸酯在医​​药中的应用及天然聚3-羟基丁酸的生物活性
    摘要：Biodegradable and biocompatible polymers, polyhydroxyalkanoates (PHAs), are actively used in medicine to produce a wide range of medical devices and dosage formulations. The medical industry mainly utilizes PHAs obtained by chemical synthesis, but interest in the medical application of natural PHAs obtained biotechnologically is also growing. Synthetic PHAs are the biomimetic analogs of bacterial poly(3-hydroxybutyrate) (PHB) and other natural PHAs. This paper addresses the issue of the presence of biological activity in synthetic and natural PHAs (stimulation of cell proliferation and differentiation, tissue regeneration) and their possible association with various biological functions of PHB in bacteria and eukaryotes, including humans.
  • 2.

    【2hr】Molecular Biomarkers of Brain and Spinal Cord Astrocytomas

    包量

    机译 脑和脊髓星形细胞瘤的分子生物标志物
    摘要：Spinal cord astrocytomas are rare diseases of the central nervous system. The localization of these tumors and their infiltrative growth complicate their surgical resection, increase the risk of postoperative complications, and require more careful use of radio- and chemotherapy. The information on the genetic mutations associated with the onset and development of astrocytomas provides a more accurate neoplasm diagnosis and classification. In some cases, it also allows one to determine the optimal methods for treating the neoplasm, as well as to predict the treatment outcomes and the risks of relapse. To date, a number of molecular markers that are associated with brain astrocytomas and possess prognostic value have been identified and described. Due to the significantly lower incidence of spinal cord astrocytomas, the data on similar markers are much more sparse and are presented with a lesser degree of systematization. However, due to the retrospective studies of clinical material that have been actively conducted abroad in recent years, the formation of statistically significant genetic landscapes for various types of tumors, including intradural spinal cord tumors, has begun. In this regard, the purposeof this review is to analyze and systematize the information on the mostsignificant genetic mutations associated with various types of astrocytomas, aswell as discuss the prospects for using the corresponding molecular markers fordiagnostic and prognostic purposes.
  • 3.

    【2hr】Targeted Drug Delivery in Lipid-like Nanocages and Extracellular Vesicles

    包量

    机译 脂质样纳米笼和细胞外囊泡中的靶向药物递送。
    摘要：The possibility of targeted drug delivery to a specific tissue, organ, or cell has opened new promising avenues in treatment development. The technology of targeted delivery aims to create multifunctional carriers that are capable of long circulation in the patient’s organism and possess low toxicity at the same time. The surface of modern synthetic carriers has high structural similarity to the cell membrane, which, when combined with additional modifications, also promotes the transfer of biological properties in order to penetrate physiological barriers effectively. Along with artificial nanocages, further efforts have recently been devoted to research into extracellular vesicles that could serve as natural drug delivery vehicles. This review provides a detailed description of targeted delivery systems that employ lipid and lipid-like nanocages, as well as extracellular vesicles with a high level of biocompatibility, highlighting genetically encoded drug delivery vehicles.
  • 4.

    【2hr】Assessment of the Phenylketonuria (PKU)-Associated Mutation p.R155H Biochemical Manifestations by Mass Spectrometry-Based Blood Metabolite Profiling

    包量

    机译 基于质谱的血液代谢产物谱分析评估苯丙酮尿症（PKU）相关突变p.R155H生化表现
    摘要：Homozygous siblings with different treatment histories represent an excellent model to study both the phenotypic manifestation of mutations and the efficacy of therapy. We compared phenylketonuria (PKU) manifestations in two different gender siblings who were homozygous carriers of a rare phenylalanine hydroxylase (PAH) mutation, p.R155H, subjected to different treatments. PKU caused by mild mutations may be easily underdiagnosed if the diagnosis is based solely on the phenylalanine (Phe) blood concentration. One of the described patients is an example of this diagnostic error. For reducing diagnostic errors, we suggest the use of more elaborate methods in screening practice, in particular mass spectrometric analysis of blood metabolites, the efficiency of which is demonstrated in the present study.
  • 5.

    【2hr】“Green” Synthesis of Cytotoxic Silver Nanoparticles Based on Secondary Metabolites of Lavandula Angustifolia Mill.

    包量

    机译 基于Lavandula Angustifolia Mill次级代谢产物的“绿色”细胞毒性银纳米粒子合成。
    摘要：In this study, we used “green” synthesis to prepare silver nanoparticles (NPs) from aqueous plant and callus extracts of the narrow-leaved lavender Lavandula angustifolia Mill. 35.4 ± 1.6 nm and 56.4 ± 2.4 nm nanoparticles, colloidally stable in phosphate-buffered saline, were synthesized using the plant extract and the callus extract, respectively. NPs were characterized by spectrophotometry, dynamic light scattering, and scanning electron microscopy. We studied the dynamics of the nanoparticle synthesis and evaluated the cytotoxic properties of the plant extract-based NPs. Modification of NPs with bovine serum albumin demonstrated that blockage of the nanoparticle surface completely suppressed NP cytotoxic activity in vitro. The synthesized NPs possess localized surface plasmon resonance properties and are of small sizes, and their surface can be modified with protein molecules, which makes them promising agents for cancer theranostics.
  • 6.

    【2hr】Septin Polymerization Slows Synaptic Vesicle Recycling in Motor Nerve Endings

    包量

    机译 Septin聚合减慢运动神经末梢中突触小泡的回收。
    摘要：Septins are GTP-binding proteins recognized as a component of the cytoskeleton. Despite the fact that septins are highly expressed by neurons and can interact with the proteins that participate in synaptic vesicle exocytosis and endocytosis, the role of septins in synaptic transmission and the synaptic vesicle recycling mechanisms is poorly understood. In this study, neurotransmitter release and synaptic vesicle exocytosis and endocytosis were investigated by microelectrode intracellular recording of end-plate potentials and fluorescent confocal microscopy in mouse diaphragm motor nerve endings during septin polymerization induced by forchlorfenuron application. It was shown that forchlorfenuron application reduces neurotransmission during prolonged high-frequency (20 and 50 pulses/s) stimulation. Application of pairs of short high-frequency stimulation trains showed that forchlorfenuron slows the replenishment of the readily releasable pool. Forchlorfenuron enhanced FM 1-43 fluorescent dye loading by synaptic vesicle endocytosis but decreased dye unloading from the preliminarily stained nerve endings by synaptic vesicle exocytosis. It was concluded that the septin polymerization induced byforchlorfenuron application slows the rate of synaptic vesicle recycling inmotor nerve endings due to the impairment of synaptic vesicle transport.
  • 7.

    【2hr】The Role of Recombinant Human Cyclophilin A in the Antitumor Immune Response

    包量

    机译 重组人亲环素A在抗肿瘤免疫反应中的作用
    摘要：Cyclophilin A (CypA) is a multifunctional protein that exhibits an isomerase activity and exists in the intracellular and secretory forms. Secretory CypA promotes regeneration of the hematopoietic and the immune systems of an organism by stimulating stem cell migration from the bone marrow. New approaches based on CypA are currently being developed for the treatment of limb ischemia, neutralization of the side effects of Cyclosporine A (CsA) therapy, etc. However, the role of CypA in the antitumor immune response is still unexplored. In this work, we used the model experimental system of lymphoma EL-4 rejection in B10.D2(R101) mice and showed that recombinant human CypA (rhCypA) stimulates the antitumor immune response via early recruitment of granulocytes to the tumor cell localization site and rapid accumulation of effector T-killers
  • 8.

    【2hr】The Differential Anti-HIV Effect of a New Humic Substance-Derived Preparation in Diverse Cells of the Immune System

    包量

    机译 一种新的由腐殖质衍生的制剂在免疫系统的多种细胞中的差异抗HIV作用
    摘要：The anti-HIV activity of a new humic substance-derived preparation has been studied in individual pools of immune cells (CD4+ T lymphocytes, macrophages, dendritic cells). Near-complete inhibition of the HIV infection (by more than 90%) was achieved by treating each of the abovementioned cell types with non-toxic concentrations of the preparation. The inhibitory effect demonstrates the possibility of preventing the depletion of a significant portion of functionally important immune cells. A comparative study of infection inhibition in individual cell pools has allowed us to reveal the differences in the preparation’s effectiveness in each of the cell populations. A R5-tropic HIV-1 infection in macrophages exhibited maximum sensitivity to the preparation: 90% and 50% inhibition of the infection were observed in the presence of concentrations as low as 1.4 and 0.35 μg/ml, respectively. A 15- and 19-fold higher concentration was required to achieve the same extent of inhibition in dendritic cells infected with the same strain. The effectiveness of the drug in CD4 + T lymphocytes is quite comparable to its effectiveness in macrophages. The drug is universally effective for both the T- and M-tropicvariants of HIV-1.
  • 9.

    【2hr】Studying the Possibilities of Using 2-Halogen-Substituted Acetamides As Acyl Donors in Penicillin Acylase-Catalyzed Reactions

    包量

    机译 研究在青霉素酰化酶催化的反应中使用2-卤素取代的乙酰胺作为酰基供体的可能性
    摘要：The possibility of using amides of halogen-substituted acetic acids as acyl donors in penicillin acylase-catalyzed reactions has been investigated, and the ability of this group of compounds to inactivate enzymes in the course of the catalytic conversion has been established. The strongest inactivating effect was demonstrated by iodoacetamide and bromoacetamide. However, the negative contribution of this side activity can be minimized by decreasing the temperature, when the rate of acyl donor conversion by penicillin acylases is still high enough, but the impact of enzyme inactivation becomes less significant. The catalytic activity of penicillin acylase from Alcaligenes faecalis in the conversion of 2-haloacetamides was significantly (5–8 times) higher than that of penicillin acylase from Escherichia coli.
  • 10.

    【2hr】The Profile of Post-translational Modifications of Histone H1 in Chromatin of Mouse Embryonic Stem Cells

    包量

    机译 小鼠胚胎干细胞染色质中组蛋白H1翻译后修饰的概况
    摘要：Linker histone H1 is one of the main chromatin proteins which plays an important role in organizing eukaryotic DNA into a compact structure. There is data indicating that cell type-specific post-translational modifications of H1 modulate chromatin activity. Here, we compared histone H1 variants from NIH/3T3, mouse embryonic fibroblasts (MEFs), and mouse embryonic stem (ES) cells using matrix-assisted laser desorption/ ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FT-ICR-MS). We found significant differences in the nature and positions of the post-translational modifications (PTMs) of H1.3-H1.5 variants in ES cells compared to differentiated cells. For instance, methylation of K75 in the H1.2-1.4 variants; methylation of K108, K148, K151, K152 K154, K155, K160, K161, K179, and K185 in H1.1, as well as of K168 in H1.2; phosphorylation of S129, T146, T149, S159, S163, and S180 in H1.1, T180 in H1.2, and T155 in H1.3 were identified exclusively in ES cells. The H1.0 and H1.2 variants in ES cells were characterized by an enhanced acetylation and overall reduced expression levels. Most of the acetylation sites of the H1.0 and H1.2 variants from ES cells were located within theirC-terminal tails known to be involved in the stabilization of the condensedchromatin. These data may be used for further studies aimed at analyzing thefunctional role played by the revealed histone H1 PTMs in the self-renewal anddifferentiation of pluripotent stem cells.
  • 11.

    【2hr】A New MicroRNA Cluster Involved in the Reprogramming to a Pluripotent State

    包量

    机译 一个新的MicroRNA集群参与重编程为多能状态。
    摘要：Reprogramming of somatic cells to a pluripotent state is a complex, multistage process that is regulated by many factors. Among these factors, non-coding RNAs and microRNAs (miRNAs) have been intensively studied in recent years. MiRNAs play an important role in many processes, particularly in cell reprogramming. In this study, we investigated the reprogramming of rat fibroblasts with a deleted locus encoding a cluster comprising 14 miRNAs (from miR-743a to miR-465). The deletion of this locus was demonstrated to decrease significantly the efficiency of the cell reprogramming. In addition, the cells produced by the reprogramming differed from rat embryonic and induced pluripotent stem cells, which was an indication that reprogramming in these cells had not been completed. We suggest that this miRNA cluster or some of its members are involved in regulating the reprogramming of rat cells to a pluripotent state.
  • 12.

    【2hr】Bacteriophage MS2 As a Tool for Targeted Delivery in Solid Tumor Chemotherapy

    包量

    机译 噬菌体MS2作为实体肿瘤化学疗法中靶向递送的工具
    摘要：Bacteriophage MS2 was employed for targeted delivery of an apoptosis-inducing agent, Tl+, into a tumor tissue. The targeted delivery was ensured by iRGD peptide, a ligand of integrins presumably located on the surface of endotheliocytes of the tumor tissue neovasculature and certain tumor cells. The synthesized peptide was conjugated to MS2 capsid proteins. Tl+ ions from TlNO3 penetrated the phage particles and tightly bound to phage RNA. Peptide-modified MS2 preparations filled with Tl+ caused cell death in two types of cultivated human breast cancer cells and effected necrosis of these tumor xenografts in mice. Neither peptide-conjugated bacteriophage MS2 without Tl+ nor the phage filled with Tl+ but without the peptide or the same phage with the non-conjugated peptide in solution produced such effects. The preparation exhibited no acute toxicity at a therapeutic dose.
  • 13.

    【2hr】Ligands of Acid-Sensing Ion Channel 1a: Mechanisms of Action and Binding Sites

    包量

    机译 酸敏感离子通道1a的配体：作用机理和结合位点
    摘要：The proton-gated cationic channels belonging to the ASIC family are widely distributed in the central nervous system of vertebrates and play an important role in several physiological and pathological processes. ASIC1a are most sensitive to acidification of the external medium, which is the reason for the current interest in their function and pharmacology. Recently, the list of ASIC1a ligands has been rapidly expanding. It includes inorganic cations, a large number of synthetic and endogenous small molecules, and peptide toxins. The information on the mechanisms of action and the binding sites of the ligands comes from electrophysiological, mutational and structural studies. In the present review, we attempt to present a systematic view of the complex pattern of interactions between ligands and ASIC1a.
  • 14.

    【2hr】Consensus Integrase of a New HIV-1 Genetic Variant CRF63_02A1

    包量

    机译 新的HIV-1基因变异CRF63_02A1的共识整合。
    摘要：The high genetic variability of the human immunodeficiency virus (HIV-1) leads to a constant emergence of new genetic variants, including the recombinant virus CRF63_02A1, which is widespread in the Siberian Federal District of Russia. We studied HIV-1 CRF63_02A1 integrase (IN_CRF) catalyzing the incorporation of viral DNA into the genome of an infected cell. The consensus sequence was designed, recombinant integrase was obtained, and its DNA-binding and catalytic activities were characterized. The stability of the IN_CRF complex with the DNA substrate did not differ from the complex stability for subtype A and B integrases; however, the rate of complex formation was significantly higher. The rates and efficiencies of 3’-processing and strand transfer reactions catalyzed by IN_CRF were found to be higher, too. Apparently, all these distinctive features of IN_CRF may result from specific amino acid substitutions in its N-terminal domain, which plays an important role in enzyme multimerization and binding to the DNA substrate. It was also found that the drug resistance mutations Q148K/G140S and G118R/E138K significantly reduce the catalytic activity of IN_CRF and its sensitivity tothe strand transfer inhibitor raltegravir. Reduction in sensitivity toraltegravir was found to be much stronger in the case of double-mutationQ148K/G140S.
  • 15.

    【2hr】Isolation, Purification and Characterization of L,D-transpeptidase 2 from Mycobacterium tuberculosis

    包量

    机译 结核分枝杆菌L，D-转肽酶2的分离，纯化和鉴定
    摘要：L,D-transpeptidase 2 from Mycobacterium tuberculosis plays a key role in the formation of nonclassical 3-3 peptidoglycan cross-links in a pathogen’s cell wall making it resistant to a broad range of penicillin antibiotics. The conditions of cultivation, isolation, and purification of recombinant L,D-transpeptidase 2 from M. tuberculosis have been optimized in this study. Oxidation of the free SH groups of catalytic cysteine Cys354 is an important factor causing the inactivation of the enzyme, which occurs during both the expression and storage of enzyme preparations. The biochemical characteristics of purified L,D-transpeptidase 2 and L,D-transpeptidase 2 lacking domain A were determined; the kinetic constants of enzyme-catalyzed nitrocefin transformation were evaluated.
  • 16.

    【2hr】Thermodynamics of the DNA Repair Process by Endonuclease VIII

    包量

    机译 核酸内切酶VIII修复DNA的热力学
    摘要：In the present work, a thermodynamic analysis of the interaction between endonuclease VIII (Endo VIII) and model DNA substrates containing damaged nucleotides, such as 5,6-dihydrouridine and 2-hydroxymethyl-3-hydroxytetrahydrofuran (F-site), was performed. The changes in the fluorescence intensity of the 1,3-diaza-2-oxophenoxazine (tC°) residue located in the complementary chain opposite to the specific site were recorded in the course of the enzyme-substrate interaction. The kinetics was analyzed by the stopped-flow method at different temperatures. The changes of standard Gibbs free energy, enthalpy, and entropy of sequential steps of DNA substrate binding, as well as activation enthalpy and entropy for the transition complex formation of the catalytic stage, were calculated. The comparison of the kinetic and thermodynamic data characterizing the conformational transitions of enzyme and DNA in the course of their interaction made it possible to specify the nature of the molecular processes occurring at the stages of substrate binding, recognition of the damaged base, and its removal from DNA.
  • 17.

    【2hr】Immunogenicity of Different Forms of Middle East Respiratory Syndrome S Glycoprotein

    包量

    机译 不同形式的中东呼吸综合征S糖蛋白的免疫原性
    摘要：The Middle East respiratory syndrome coronavirus (MERS-CoV) was identified in 2012 during the first Middle East respiratory syndrome (MERS) outbreaks. MERS-CoV causes an acute lower-respiratory infection in humans, with a fatality rate of ~35.5%. Currently, there are no registered vaccines or means of therapeutic protection against MERS in the world. The MERS-CoV S glycoprotein plays the most important role in the viral life cycle (virus internalization). The S protein is an immunodominant antigen and the main target for neutralizing antibodies. In the present study, the immunogenicities of five different forms of the MERS-CoV S glycoprotein were compared: the full-length S glycoprotein, the full-length S glycoprotein with the transmembrane domain of the G glycoprotein of VSV (S-G), the receptor-binding domain (RBD) of the S glycoprotein, the membrane-fused RBD (the RBD fused with the transmembrane domain of the VSV G glycoprotein (RBD-G)), and the RBD fused with Fc of human IgG1 (RBD-Fc). Recombinant vectors based on human adenoviruses type 5 (rAd5) were used as delivery vehicles. Vaccination with all of the developed rAd5 vectors elicited a balanced Th1/Th2 response in mice. The most robust humoralimmune response was induced after the animal had been vaccinated with themembrane-fused RBD (rAd5-RBD-G). Only immunization with membrane forms of theglycoprotein (rAd5-S, rAd5-S-G, and rAd5-RBD-G) elicited neutralizingantibodies among all vaccinated animals. The most significant cellular immuneresponse was induced after vaccination of the animals with the full-length S(rAd5-S). These investigations suggest that the full-length S and the membraneform of the RBD (RBD-G) are the most promising vaccine candidates among all thestudied forms of S glycoprotein.
  • 18.

    【2hr】A Novel Dipeptide NGF Mimetic GK-2 Selectively Activating the PI3K/AKT Signaling Pathway Promotes the Survival of Pancreatic β-Cells in a Rat Model of Diabetes

    包量

    机译 选择性激活PI3K / AKT信号通路的新型二肽NGF模拟GK-2促进糖尿病大鼠模型中胰腺β细胞的存活。
    摘要：We investigated the cytoprotective effect of a novel low-molecular-weight NGF mimetic, GK-2 (hexamethylenediamide bis-N-monosuccinyl-L-glutamyl-L-lysine), on pancreatic β-cells. The neuroprotective effect of GK-2 had been previously shown to be associated with selective activation of the PI3K/Akt signaling pathway. In this study, rats with streptozotocin (STZ)-induced type 2 diabetes mellitus were used. Metformin was used as a reference drug. STZ was immunohistochemically demonstrated to reduce the number of β-cells and affect their morphological structure. Treatment of diabetic animals with GK-2 (at a dose of 0.5 mg/kg intraperitoneally or 5 mg/kg orally) or metformin (300 mg/kg orally) for 28 days reduced the damaging effect of STZ. The effect of GK-2 on manifestations of STZ-induced diabetes, such as hyperglycemia, weight loss, polyphagia, and polydipsia, was comparable to that of metformin, while the cytoprotective activity of GK-2 was slightly stronger than that of metformin. A strong positive correlation between morphometric parameters and the blood glucose level was revealed. The GK-2 cytoprotective effect on β-cells is supposed to manifest through the PI3K/Akt signaling pathway.
  • 19.

    【2hr】Structure of the Anti-C60 Fullerene Antibody Fab Fragment: Structural Determinants of Fullerene Binding

    包量

    机译 抗C60富勒烯抗体Fab片段的结构：富勒烯结合的结构决定因素。
    摘要：The structure of the anti-C60 fullerene antibody Fab fragment (FabC60) was solved by X-ray crystallography. The computer-aided docking of C60 into the antigen-binding pocket of FabC60 showed that binding of C60 to FabC60 is governed by the enthalpy and entropy; namely, by π-π stacking interactions with aromatic residues of the antigen-binding site and reduction of the solvent-accessible area of the hydrophobic surface of C60. A fragment of the mobile CDR H3 loop located on the surface of FabC60 interferes with C60 binding in the antigen-binding site, thereby resulting in low antibody affinity for C60. The structure of apo-FabC60 has been deposited with pdbid 6H3H.
  • 20.

    【2hr】Adaptation of the Newcastle Disease Virus to Cell Cultures for Enhancing Its Oncolytic Properties

    包量

    机译 新城疫病毒适应细胞培养以增强其溶瘤特性
    摘要：This study focuses on the adaptation of natural Newcastle disease virus (NDV) strains isolated from wild birds to human tumor cells. Many candidates for virotherapy are viruses pathogenic for human. During recombination of genetic material, there always exists a risk of getting a virus with an unstable genome. This problem can be solved by using natural apathogenic viruses as oncolytic agents. The Newcastle disease virus is the causative agent of contagious avian diseases. Its natural strains exhibit an antitumor effect and are considered safe for humans. As shown in earlier studies, the oncolytic properties of natural strains can be enhanced during adaptation to cell cultures, without interference in the virus genome. This study demonstrates that serial passaging increases the viral infectious titer in cancer cells. Moreover, the viability of tumor cells decreases post-infection when Newcastle disease virus strains are adapted to these cell cultures. The findings of this study complement the well-known data on the adaptation of the Newcastle disease virus to human cancer cells. Hence, it is possible to obtain a NDV strain with a more pronounced oncolytic potential during adaptation. This should be takeninto account when choosing a strategy for designing anticancer drugs based onthis virus.
题名 作者 来源 发表时间

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号