MS2

PURPOSE: A challenge for medical educators is choosing a method that best evaluates preclinical students' performance in preparation for Step 1. In previous years, block directors (BDs) of the 2nd year (MS2) neuroscience course at Texas Tech University Health Sciences Center School of Medicine issued faculty-written (FW) examinations during the course. In 2022, BDs replaced FW examinations with National Board of Medical Examiners (NBME) custom examinations. The rationale being that the customized NBME exams would better reflect the national neuroscience curriculum and enhance student preparedness for taking standardized exams...

RATIONALE: The study addresses the challenge of identifying RNA post-transcriptional modifications when commercial standards are not available to generate reference spectral libraries. It proposes employing homologous nucleobases and deoxyribonucleosides as alternative reference spectral libraries to aid in identifying modified ribonucleosides and distinguishing them from their positional isomers when the standards are unavailable. METHODS: Complete sets of ribonucleoside, deoxyribonucleoside and nucleobase standards were analyzed using high-performance nano-flow liquid chromatography coupled to an Orbitrap Eclipse Tribrid mass spectrometer...

The treatment of waterborne micropollutants, such as diclofenac, presents a significant challenge to wastewater treatment plants due to their incomplete removal by conventional methods. Ozonation is an effective technique for the degradation of micropollutants. However, incomplete oxidation can lead to the formation of ecotoxic by-products that require a subsequent post-treatment step. In this study, we analyze the susceptibility of micropollutant ozonation products to enzymatic digestion with laccase from Trametes versicolor to evaluate the potential of enzymatic treatment as a post-ozonation step...

BACKGROUND: As one of the most famous natural products, salvianolic acid A (SAA) is undergoing clinical trials for the treatments of angina pectoris and coronary heart disorders. However, the in vivo metabolites of SAA have only been tentatively identified, leading to a barrier for precise therapeutical drug monitoring. METHODS: Ultra-high performance liquid chromatography coupled with quadrupole time of flight tandem mass spectrometry (UPLC-Qtof-MS/MS) was firstly employed to acquire high-resolution MS1 and MS2 spectra for all metabolites...

Viral infections pose a significant threat to public health, and the production of interferons represents one of the most critical antiviral innate immune responses of the host. Consequently, the screening and identification of compounds or reagents that induce interferon production are of paramount importance. This study commenced with the cultivation of host bacterium 15,597, followed by the infection of Escherichia coli with the MS2 bacteriophage. Utilizing the J2 capture technique, a class of dsRNA mixtures (MS2+15,597) was isolated from the E...

BACKGROUND: Hypertension is a global issue that is projected to worsen with increasingly obese populations. The central nervous system including the parts of the cortex plays a key role in hemodynamic stability and homeostatic control of blood pressure (BP), making them critical components in understanding and investigating the neural control of BP. This study investigated the effects of anodal transcranial direct current stimulation (tDCS) associated with aerobic physical exercise on BP and heart rate variability in hypertensive patients...

The Human Papillomavirus (HPV) is a sexually transmitted infection that significantly affects the population worldwide. HPV preventive methods include vaccination, prophylactics, and education. Different types of cancers associated with HPV usually take years or decades to develop after infections, such as Head and Neck Cancer(HNC). Therefore, HPV prevention can be considered cancer prevention. A sample of medical students in Puerto Rico was evaluated to assess their knowledge about HPV, HPV vaccine, and HNC through two previously validated online questionnaires composed of 38 dichotomized questions, we measured HPV, HPV vaccination(HPVK), and HNC knowledge (HNCK)...

BACKGROUND AND PURPOSE: White adipose tissue (WAT) is involved in rheumatoid arthritis (RA). This study explored its potential as an antirheumatic target. EXPERIMENTAL APPROACH: WAT status of healthy and adjuvant-induced arthritis (AIA) rats were compared. The contribution of WAT to RA pathology was evaluated by pre-adipocyte transplant experiments and by dissecting perirenal fat pads of AIA rats. The impact of RA on WAT was investigated by culturing pre-adipocytes...

BACKGROUND: There are a lot of studies on the treatment of tumors with hyperbaric oxygen, while most of them are in breast cancer, prostate cancer and so on. However, there are still few studies on hyperbaric oxygen in treating hepatocellular carcinoma (HCC). According to the current data, hyperbaric oxygen is an effective means to intervene in tumors. The Warburg effect is a unique marker of glucose metabolism in tumors related to hypoxia, making it possible for hyperbaric oxygen to interfere with the tumor through the Warburg effect...

Identification of stereo- and positional isomers detected with high-resolution mass spectrometry (HRMS) is often challenging due to near-identical fragmentation spectra (MS2 ), similar retention times, and collision cross-section values (CCS). Here we address this challenge on the example of hydroxylated polychlorinated biphenyls (OH-PCBs) with the aim to (1) distinguish between isomers of OH-PCBs using two-dimensional ion mobility spectrometry (2D-IMS) and (2) investigate the structure of the fragments of OH-PCBs and their fragmentation mechanisms by ion mobility spectrometry coupled to high-resolution mass spectrometry (IMS-HRMS)...

To understand the mode of action of bioactive oligosaccharides, such as prebiotics, in-depth knowledge about all structural features, including monosaccharide composition, linkage type, and anomeric configuration, is necessary. Current analytical techniques provide limited information about structural features within complex mixtures unless preceded by extensive purification. In this study, we propose an approach employing cyclic ion mobility spectrometry (cIMS) for the in-depth characterization of oligosaccharides, here demonstrated for disaccharides...

The versatile potential of bacteriophage MS2-derived virus-like particles (VLPs) in medical biotechnology has been extensively studied during the last 30 years. Since the first reports showing that MS2 VLPs can be produced at high yield and relatively easily engineered, numerous applications have been proposed. Particular effort has been spent in developing MS2 VLPs as protective capsules and delivery platforms for diverse molecules, such as chemical compounds, proteins and nucleic acids. Among these, two are particularly noteworthy: as scaffolds displaying heterologous epitopes for vaccine development and as capsids for encapsulation of foreign RNA...

The comprehensive detection and identification of active ingredients in complex matrices is a crucial challenge. Liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS) is the most prominent analytical platform for the exploration of novel active compounds from complex matrices. However, the LC-HRMS-based analysis workflow suffers from several bottleneck issues, such as trace content of target compounds, limited acquisition for fragment information, and uncertainty in interpreting relevant MS2 spectra...

Phytosterols are lipophilic compounds found in plants with structural similarity to mammalian cholesterol. They cannot be endogenously produced by mammals and therefore always originate from diet. There has been increased interest in dietary phytosterols over the last few decades due to their association with a variety of beneficial health effects including low-density lipoprotein cholesterol lowering, anti-inflammatory and anti-cancerous effects. They are proposed as potential moderators for diseases associated with the central nervous system where cholesterol homeostasis is found to be imperative (multiple sclerosis, dementia, etc...

Endotoxins are toxic lipopolysaccharides (LPSs), extending from the outer membrane of Gram-negative bacteria and notorious for their toxicity and deleterious effects. The comparison of different LPSs, isolated from various Gram-negative bacteria, shows a global similar architecture corresponding to a glycolipid lipid A moiety, a core oligosaccharide, and outermost long O-chain polysaccharides with molecular weights from 2 to 20 kDa. LPSs display high diversity and specificity among genera and species, and each bacterium contains a unique set of LPS structures, constituting its protective external barrier...

We report the discovery of a novel cyclic nonribosomal peptide (NRP), acyl-surugamide A2, from a marine-derived Streptomyces albidoflavus RKJM-0023 (CP133227). The structure of acyl-surugamide A2 was elucidated using a combination of NMR spectroscopy, MS2 fragmentation analysis, and comparative analysis of the sur biosynthetic gene cluster. Acyl-surugamide A2 contains all eight core amino acids of surugamide A, with a modified N-ε-acetyl-L-lysine residue. Our study highlights the potential of marine Streptomyces strains to produce novel natural products with potential therapeutic applications...

In our quest to discover advanced glycation end products (AGEs) inhibitors from Clinacanthus nutans (Burm.f.) Lindau leaves, we conducted Bioactive Molecular Networking. This approach integrates LC-MS2 profiling and in vitro antiglycation data to predict bioactive compounds. We began by screening three extracts: 100% ethanol, 70% ethanol and 100% water alongside the in vitro antioxidant activity, total phenolics content (TPC) and schaftoside content. Among these extracts, 100% ethanol extract exhibited the highest total AGEs inhibition effects (IC50  = 80...

Brucea javanica, a valued traditional medicinal plant in Malaysia, known for its fever-treating properties yet remains underexplored for its potential antiviral properties against dengue. This study aims to simultaneously identify chemical classes and metabolites within B. javanica using molecular networking (MN), by Global Natural Product Social (GNPS), and SIRIUS in silico annotation. Liquid chromatography-mass spectrometry (LC-MS2) -based MN explores chemical diversity across four plant parts (leaves, roots, fruits, and stem bark), revealing diverse metabolites such as tryptophan-derived alkaloids, terpenoids, and octadecadenoids...

Early diagnosis is paramount for enhancing survival rates and prognosis in the context of malignant diseases. Hepatocellular carcinoma (HCC), the second leading cause of cancer-related deaths worldwide, poses significant challenges for its early detection. In this study, we present an innovative approach which contributed to the early diagnosis of HCC. By lanthanide encoding signal amplification to map glycan-linkages at the single-cell level, the minute quantities of "soft" glycan-linkages on single cell surface were converted into "hard" elemental tags through the use of an MS2 signal amplifier...

Bioaerosols play a significant role in the transmission of many infectious diseases, especially in enclosed indoor environments. Ultraviolet (UV) disinfection has demonstrated a high efficacy in inactivating microorganisms suspended in the air. To develop more effective and efficient UV disinfection protocols, it is necessary to evaluate and optimize the effectiveness of UV disinfection against aerosolized bacteria and viruses across the entire UV spectrum. In this study, we evaluated the performance of UV disinfection across the UV spectrum, ranging from 222 to 365 nm, against aerosolized bacteria and viruses, including Escherichia coli , Staphylococcus epidermidis , Salmonella enterica , MS2, P22, and Phi6...