Navigating the metabolic maze: anomalies in fatty acid and cholesterol processes in Alzheimer's astrocytes.

Alzheimer's disease (AD) is the most common cause of dementia, and its underlying mechanisms have been a subject of great interest. The mainstream theory of AD pathology suggests that the disease is primarily associated with tau protein and amyloid-beta (Aβ). However, an increasing body of research has revealed that abnormalities in lipid metabolism may be an important event throughout the pathophysiology of AD.

Assessment of health risk and dose-effect of DNA oxidative damage for the thirty chemicals mixture of parabens, triclosan, benzophenones, and phthalate esters.

Humans are constantly exposed to parabens (PBs), triclosan (TCS), benzophenones (BPs), and phthalate esters (PAEs) due to the widespread existence of these chemicals in personal care products (PCPs), and the high frequency of usage for humans. Previous studies indicated each class of the above-mentioned chemicals can exhibit potential adverse effects on humans, in particular DNA oxidative damage. However, the health risk assessment of combined exposures to multiple PCPs is limited, especially the overall dose-effect of mixtures of these chemicals on DNA oxidative damage.

Assessment of the Components of the Electrostatic Potential of Proteins in Solution: Comparing Experiment and Theory.

In this work, the components of the protein electrostatic potentials in solution are analyzed with NMR paramagnetic relaxation enhancement experiments and compared with continuum solution theory, and multiscale simulations. To determine the contributions of the solution components, we analyze them at different ionic strengths from 0 to 745 mM. A theoretical approximation allows the determination of the electrostatic potential at a given proton without reference to the protein structure given the ratio of paramagnetic relaxation enhancements rates between a cationic and an anionic probe.

The Effects of Flexibility on dsDNA-dsDNA Interactions.

A detailed understanding of the physical mechanism of ion-mediated dsDNA interactions is important in biological functions such as DNA packaging and homologous pairing. We report the potential of mean force (PMF) or the effective solvent mediated interactions between two parallel identical dsDNAs as a function of interhelical separation in 0.15 M NaCl solution.

A toxicity pathway-based approach for modeling the mode of action framework of lead-induced neurotoxicity.

Background: The underlying mechanisms of lead (Pb) toxicity are not fully understood, which makes challenges to the traditional risk assessment. There is growing use of the mode of action (MOA) for risk assessment by integration of experimental data and system biology. The current study aims to develop a new pathway-based MOA for assessing Pb-induced neurotoxicity.

MiR-486-5p-directed MAGI1/Rap1/RASSF5 signaling pathway contributes to hydroquinone-induced inhibition of erythroid differentiation in K562 cells.

Bone marrow failure is a characteristic effect of benzene exposure. Our previous study has shown that miR-486-5p is involved in benzene induced-suppression of erythroid differentiation. However, the mechanism of miR-486-5p to initiate the above process remains unclear.

Mobility of Histidine Side Chains Analyzed with N NMR Relaxation and Cross-Correlation Data: Insight into Zinc-Finger-DNA Interactions.

Due to chemical exchange, the mobility of histidine (His) side chains of proteins is typically difficult to analyze by NMR spectroscopy. Using an NMR approach that is uninfluenced by chemical exchange, we investigated internal motions of the His imidazole NH groups that directly interact with DNA phosphates in the Egr-1 zinc-finger-DNA complex. In this approach, the transverse and longitudinal cross-correlation rates for N chemical shift anisotropy and N-H dipole-dipole relaxation interference were analyzed together with N longitudinal relaxation rates and heteronuclear Overhauser effect data at two magnetic field strengths.

NMR Methods for Characterizing the Basic Side Chains of Proteins: Electrostatic Interactions, Hydrogen Bonds, and Conformational Dynamics.

NMR spectroscopy is a powerful tool for studying protein dynamics. Conventionally, NMR studies on protein dynamics have probed motions of protein backbone NH, side-chain aromatic, and CH groups. Recently, there has been remarkable progress in NMR methodologies that can characterize motions of cationic groups in protein side chains.

Superior success rate of intracavitary electrocardiogram guidance for peripherally inserted central catheter placement in patients with cancer: A randomized open-label controlled multicenter study.

Background: Intracavitary electrocardiogram (IC ECG) guidance emerges as a new technique for peripherally inserted central catheters (PICCs) placement and demonstrates many potential advantages in recent observational studies.

Aims: To determine whether IC ECG-guided PICCs provide more accurate positioning of catheter tips compared to conventional anatomical landmarks in patients with cancer undergoing chemotherapy.

Methods: In this multicenter, open-label, randomized controlled study (ClinicalTrials.

Changes in conformational dynamics of basic side chains upon protein-DNA association.

Basic side chains play major roles in recognition of nucleic acids by proteins. However, dynamic properties of these positively charged side chains are not well understood. In this work, we studied changes in conformational dynamics of basic side chains upon protein-DNA association for the zinc-finger protein Egr-1.

DNA Shape versus Sequence Variations in the Protein Binding Process.

The binding process of a protein with a DNA involves three stages: approach, encounter, and association. It has been known that the complexation of protein and DNA involves mutual conformational changes, especially for a specific sequence association. However, it is still unclear how the conformation and the information in the DNA sequences affects the binding process.

Dynamic Equilibria of Short-Range Electrostatic Interactions at Molecular Interfaces of Protein-DNA Complexes.

Intermolecular ion pairs (salt bridges) are crucial for protein-DNA association. For two protein-DNA complexes, we demonstrate that the ion pairs of protein side-chain NH3+ and DNA phosphate groups undergo dynamic transitions between distinct states in which the charged moieties are either in direct contact or separated by water. While the crystal structures of the complexes show only the solvent-separated ion pair (SIP) state for some interfacial lysine side chains, our NMR hydrogen-bond scalar coupling data clearly indicate the presence of the contact ion pair (CIP) state for the same residues.

[Clinical observation of telbivudine's antiviral efficacy and protection against mother-to-infant transmission of chronic hepatitis B during the first trimester of pregnancy].

Objective: To explore the antiviral efficacy, safety and protective ability against mother-to-infant transmission of telbivudine in pregnant patients with chronic hepatitis B (CHB) during the first trimester.

Methods: Eighty four gravid women who were diagnosed with CHB, in their first trimester of pregnancy, and had refused to terminate their pregnancies were enrolled; all study participants were clinically classified as active hepatitis cases with positivity for both hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg), HBV DNA more than or equal to 107 copies/mL and serum level of alanine aminotarnsferase (ALT) of more than or equal to 4 ULN.Patients with YMDD mutations were excluded from the study.

Comparison of complications of peripherally inserted central catheters with ultrasound guidance or conventional methods in cancer patients.

Objective: To compare the complications of peripherally inserted central catheters (PICC) by a modified Seldinger technique under ultrasound guidance or the conventional (peel-away cannula) technique.

Methods: From February to December of 2010, cancer patients who received PICC at the Department of Chemotherapy in Jiangsu Cancer Hospital were recruited into this study, and designated UPICC if their PICC lines were inserted under ultrasound guidance, otherwise CPICC if were performed by peel-away cannula technique. The rates of successful placement, hemorrhage around the insertion area, phlebitis, comfort of the insertion arm, infection and thrombus related to catheterization were analyzed and compared on days 1, 5 and 6 after PICC and thereafter.

The binding process of a nonspecific enzyme with DNA.

Protein-DNA recognition of a nonspecific complex is modeled to understand the nature of the transient encounter states. We consider the structural and energetic features and the role of water in the DNA grooves in the process of protein-DNA recognition. Here we have used the nuclease domain of colicin E7 (N-ColE7) from Escherichia coli in complex with a 12-bp DNA duplex as the model system to consider how a protein approaches, encounters, and associates with DNA.

Advantage of being a dimer for Serratia marcescens endonuclease.

The monomer and dimer of the bacterium Serratia marcescens endonuclease (SMnase) are each catalytically active, and the two subunits of the dimer function independently of each other. Nature, however, chooses the dimer form instead of the monomer. In order to explain this, we performed molecular dynamics (MD) simulations of both model-built complexes of a subunit of SMnase and the dimer with DNA in aqueous solution.

Effects of dimerization of Serratia marcescens endonuclease on water dynamics.

The dynamics and structure of Serratia marcescens endonuclease and its neighboring solvent are investigated by molecular dynamics (MD). Comparisons are made with structural and biochemical experiments. The dimer form is physiologic and functions more processively than the monomer.

Solvent participation in Serratia marcescens endonuclease complexes.

The monomer and dimer of the bacterium Serratia marcescens endonuclease (SMnase) are each catalytically active and the two subunits of the dimer function independently of each other. Specific interfacial waters may play a role in stability, complex formation, and functionality. We performed molecular dynamics simulations of both a subunit of SMnase and its model built complex with DNA and analyzed the relation of the hydration sites to the catalytic mechanism.

Use of T4 lysozyme charge mutants to examine electrophoretic models.

The electrophoretic mobility of a macro-ion is affected in a complex manner by a variety of forces that arise from the applied field. Coupling of the macro-ion and small-ion flows gives rise to non-conserved forces that are greater than those expected from ordinary hydrodynamic considerations. It is difficult to separate the steady-state hydrodynamic and electrodynamic contributions to the macro-ion mobility.