Biosynthesis, regulation, and biological significance of fumonisins in fungi: current status and prospects

2021 ◽  
pp. 1-13
Author(s):  
Taotao Li ◽  
Xinguo Su ◽  
Hongxia Qu ◽  
Xuewu Duan ◽  
Yueming Jiang
Keyword(s):  
Biological Significance ◽  
Current Status ◽  
Biosynthesis Regulation

scholarly journals Molecular Characterization of Collagen Hydroxylysine O-Glycosylation by Mass Spectrometry: Current Status

2013 ◽  
Vol 66 (7) ◽  
pp. 760 ◽  
Author(s):  
Irina Perdivara ◽  
Mitsuo Yamauchi ◽  
Kenneth B. Tomer
Keyword(s):  
Mass Spectrometry ◽  
Type I Collagen ◽  
Molecular Mapping ◽  
Biological Significance ◽  
The Body ◽  
Current Status ◽  
Future Research ◽  
Type I ◽  
Post Translational Modifications

The most abundant proteins in vertebrates – the collagen family proteins – play structural and biological roles in the body. The predominant member, type I collagen, provides tissues and organs with structure and connectivity. This protein has several unique post-translational modifications that take place intra- and extra-cellularly. With growing evidence of the relevance of such post-translational modifications in health and disease, the biological significance of O-linked collagen glycosylation has recently drawn increased attention. However, several aspects of this unique modification – the requirement for prior lysyl hydroxylation as a substrate, involvement of at least two distinct glycosyl transferases, its involvement in intermolecular crosslinking – have made its molecular mapping and quantitative characterization challenging. Such characterization is obviously crucial for understanding its biological significance. Recent progress in mass spectrometry has provided an unprecedented opportunity for this type of analysis. This review summarizes recent advances in the area of O-glycosylation of fibrillar collagens and their characterization using state-of-the-art liquid chromatography–mass spectrometry-based methodologies, and perspectives on future research. The analytical characterization of collagen crosslinking and advanced glycation end-products are not addressed here.

scholarly journals Current Status and Perspectives of Patient-Derived Models for Ewing’s Sarcoma

Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2520
Author(s):  
Tadashi Kondo
Keyword(s):  
Cell Lines ◽  
Molecular Mechanisms ◽  
Ewing’S Sarcoma ◽  
Ewing's Sarcoma ◽  
Model Development ◽  
Biological Significance ◽  
Current Status ◽  
Antitumor Effects ◽  
Molecular Features ◽  
Cancer Models

Patient-derived cancer models, including cell lines, organoids, and xenografts, are indispensable tools in cancer research. These models, which recapitulate molecular features of original tumors, allow studies on the biological significance of cancer-associated genes, antitumor effects of novel agents, and molecular mechanisms underlying clinical behaviors of tumors. Moreover, the predictive utility of patient-derived cancer models is expected to facilitate drug development and precision medicine. Ewing’s sarcoma is a highly aggressive mesenchymal tumor with a high metastasis rate. Previous studies demonstrated the utility of cell lines and xenografts in Ewing’s sarcoma research and clinical studies. However, the number of Ewing’s sarcoma models available from public biobanks is limited; this creates an obstacle for research on Ewing’s sarcoma. Novel Ewing’s sarcoma models are needed to establish their utility, further our understanding of the molecular mechanisms, and help develop effective therapeutic strategies. In this review, the current status of patient-derived cancer models is overviewed, and future prospects of model development are discussed from the perspective of Ewing’s sarcoma research. It should be of interest to researchers and clinicians who work on patient-derived cancer models.

scholarly journals A Dual Face of APE1 in the Maintenance of Genetic Stability in Monocytes: An Overview of the Current Status and Future Perspectives

Genes ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 643
Author(s):  
Gabriela Betlej ◽  
Ewelina Bator ◽  
Antoni Pyrkosz ◽  
Aleksandra Kwiatkowska
Keyword(s):  
Genetic Stability ◽  
Molecular Mechanisms ◽  
Excision Repair ◽  
Biological Significance ◽  
Dna Lesions ◽  
Current Status ◽  
Dna Breaks ◽  
Antioxidant Genes ◽  
Double Strand Dna Breaks ◽  
Base Excision

Monocytes, which play a crucial role in the immune system, are characterized by an enormous sensitivity to oxidative stress. As they lack four key proteins responsible for DNA damage response (DDR) pathways, they are especially prone to reactive oxygen species (ROS) exposure leading to oxidative DNA lesions and, consequently, ROS-driven apoptosis. Although such a phenomenon is of important biological significance in the regulation of monocyte/macrophage/dendritic cells’ balance, it also a challenge for monocytic mechanisms that have to provide and maintain genetic stability of its own DNA. Interestingly, apurinic/apyrimidinic endonuclease 1 (APE1), which is one of the key proteins in two DDR mechanisms, base excision repair (BER) and non-homologous end joining (NHEJ) pathways, operates in monocytic cells, although both BER and NHEJ are impaired in these cells. Thus, on the one hand, APE1 endonucleolytic activity leads to enhanced levels of both single- and double-strand DNA breaks (SSDs and DSBs, respectively) in monocytic DNA that remain unrepaired because of the impaired BER and NHEJ. On the other hand, there is some experimental evidence suggesting that APE1 is a crucial player in monocytic genome maintenance and stability through different molecular mechanisms, including induction of cytoprotective and antioxidant genes. Here, the dual face of APE1 is discussed.

scholarly journals Targeting the 5-HT2C Receptor in Biological Context and the Current State of 5-HT2C Receptor Ligand Development

2019 ◽  
Vol 19 (16) ◽  
pp. 1381-1398 ◽  
Author(s):  
Eric A. Wold ◽  
Christopher T. Wild ◽  
Kathryn A. Cunningham ◽  
Jia Zhou
Keyword(s):  
Biological Significance ◽  
Current Status ◽  
Allosteric Modulators ◽  
Class A ◽  
Current State ◽  
The Central Nervous System ◽  
Treatment Of Obesity ◽  
And Function ◽  
Anxiety Depression ◽  
G Protein Coupled

Serotonin (5-HT) 5-HT2C receptor (5-HT2CR) is recognized as a critical mediator of diseaserelated pathways and behaviors based upon actions in the central nervous system (CNS). Since 5-HT2CR is a class A G protein-coupled receptor (GPCR), drug discovery efforts have traditionally pursued the activation of the receptor through synthetic ligands with agonists proposed for the treatment of obesity, substance use disorders and impulse control disorders while antagonists may add value for the treatment of anxiety, depression and schizophrenia. The most significant agonist discovery to date is the FDAapproved anti-obesity medication lorcaserin. In recent years, efforts towards developing other mechanisms to enhance receptor function have resulted in the discovery of Positive Allosteric Modulators (PAMs) for the 5-HT2CR, with several molecule series now reported. The biological significance and context for signaling and function of the 5-HT2CR, and the current status of 5-HT2CR agonists and PAMs are discussed in this review.

Current status of special planetary and lunar theories and ephemerides

1966 ◽  
Vol 25 ◽  
pp. 266-267
Author(s):  
R. L. Duncombe
Keyword(s):  
Observational Data ◽  
Current Status ◽  
Numerical Errors

An examination of some specialized lunar and planetary ephemerides has revealed inconsistencies in the adopted planetary masses, the presence of non-gravitational terms, and some outright numerical errors. They should be considered of temporary usefulness only, subject to subsequent amendment as required for the interpretation of observational data.

Microstructural morphology of sphingolipid dispersions as investigated by freeze-fracture EM

1995 ◽  
Vol 53 ◽  
pp. 944-945
Author(s):  
Vitthal S. Kulkarni ◽  
Wayne H. Anderson ◽  
Rhoderick E. Brown
Keyword(s):  
Acyl Chain ◽  
Biological Significance ◽  
Freeze Fracture ◽  
Fatty Acyl ◽  
Fatty Acyl Moiety ◽  
Aqueous Dispersions ◽  
Head Groups ◽  
Lipid Species ◽  
Microstructural Morphology ◽  
Layer Chromatography

The biological significance of the sphingomyelins (SM) and monoglycosylated sphingolipids like galactosylceramides (GalCer) are well documented Our recent investigation showed tubular bilayers in the aqueous dispersions of N-nervonoyl GalCer [N-(24:lΔ15,cls) GalCer] (a major fatty acyl moiety of natural GalCer). To determine the influence of lipid head groups on the resulting mesophasic morphology, we investigated microstructural self-assemblies of N-nervonoyl-SM [N-(24:1 Δ15,cls) SM; the second most abundant sphingomyelin in mammalian cell membranes], 1- palmitoyl-2-nervonoyl phosphatidylcholine [PNPC] (the lipid species with the same acyl chain configuration as in N-(24: 1) GalCer) and also compared it with egg-SM by freeze-fracture EM.Procedures for synthesizing and purifying N-(24:1) GalCer, N-(24:1) SM, and PNPC have been reported . Egg-SM was purchased from Avanti Polar Lipids, Alabaster AL. All lipids were >99% pure as checked by thin layer chromatography. Lipid dispersions were prepared by hydrating dry lipid with phosphate buffer (pH 6.6) at 80-90°C (3-5 min), vigorously vortexing (1 min) and repeating this procedure for three times prior to three freeze-thaw cycles.

Current Status of Solid-State X-Ray Systems

1985 ◽  
Vol 43 ◽  
pp. 158-161
Author(s):  
Martin Peckerar ◽  
Anastasios Tousimis
Keyword(s):  
Solid State ◽  
Electric Fields ◽  
Spectral Lines ◽  
Current Status ◽  
Mobile Charge ◽  
Electron Hole ◽  
X Ray ◽  
Sensing Systems ◽  
Transmission Electron ◽  
Electron Microscopes

Solid state x-ray sensing systems have been used for many years in conjunction with scanning and transmission electron microscopes. Such systems conveniently provide users with elemental area maps and quantitative chemical analyses of samples. Improvements on these tools are currently sought in the following areas: sensitivity at longer and shorter x-ray wavelengths and minimization of noise-broadening of spectral lines. In this paper, we review basic limitations and recent advances in each of these areas. Throughout the review, we emphasize the systems nature of the problem. That is. limitations exist not only in the sensor elements but also in the preamplifier/amplifier chain and in the interfaces between these components.Solid state x-ray sensors usually function by way of incident photons creating electron-hole pairs in semiconductor material. This radiation-produced mobile charge is swept into external circuitry by electric fields in the semiconductor bulk.

Ultrastructural Localization Study of Carcinoembryonic Antigen (CEA) in Gastric Cancer: Immunoelectron Microscopic Observation

1990 ◽  
Vol 48 (3) ◽  
pp. 252-253
Author(s):  
Dong Yuming ◽  
Yang Guanglin ◽  
Wu Jifeng ◽  
Chen Xiaolin
Keyword(s):  
Gastric Cancer ◽  
Intestinal Metaplasia ◽  
Cancer Cells ◽  
Microscopic Observation ◽  
Biological Significance ◽  
Ultrastructural Localization ◽  
Mucinous Carcinoma ◽  
Surface Glycoprotein ◽  
Tubular Adenocarcinoma ◽  
Pap Method

On the basis of light microscopic observation, the ultrastructural localization of CEA in gastric cancer was studied by immunoelectron microscopic technique. The distribution of CEA in gastric cancer and its biological significance and the mechanism of abnormal distribution of CEA were further discussed.Among 104 surgically resected specimens of gastric cancer with PAP method at light microscopic level, the incidence of CEA(+) was 85.58%. All of mucinous carcinoma exhibited CEA(+). In tubular adenocarcinoma the incidence of CEA(+) showed a tendency to rising with the increase of degree of differentiation. In normal epithelia and intestinal metaplasia CEA was faintly present and was found only in the luminal surface. The CEA staining patterns in cancer cells were of three types--- cytoplasmic, membranous and weak reactive type. The ultrastructural localization of CEA in 14 cases of gastric cancer was studied by immunoelectron microscopic technique.There was a little or no CEA in the microvilli of normal epithelia. In intestinal metaplasia CEA was found on the microvilli of absorptive cells and among the mucus particles of goblet cells. In gastric cancer CEA was also distributed on the lateral and basal surface or even over the entire surface of cancer cells and lost their polarity completely. Many studies had proved that the alterations in surface glycoprotein were characteristic changes of tumor cells. The antigenic determinant of CEA was glycoprotein, so the alterations of tumor-associated surface glycoprotein opened up a new way for the diagnosis of tumors.

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