Amino Acid Sequence of Oligopeptide Causes Marked Difference in DNA Compaction and Transcription.

Compaction of T4 phage DNA (166 kbp) by short oligopeptide octamers composed of two types of amino acids, four cationic lysine (K), and four polar nonionic serine (S) having different sequence order was studied by single-molecule fluorescent microscopy. We found that efficient DNA compaction by oligopeptide octamers depends on the geometrical match between phosphate groups of DNA and cationic amines. The amino acid sequence order in octamers dramatically affects the mechanism of DNA compaction, which changes from a discrete all-or-nothing coil-globule transition induced by a less efficient (KS) octamer to a continuous compaction transition induced by a (KS) octamer with a stronger DNA-binding character.

B-type natriuretic peptide response and reverse left ventricular remodeling after surgical correction of functional mitral regurgitation in patients with advanced cardiomyopathy.

Background: Restrictive mitral annuloplasty (RMA) can reverse left ventricular (LV) remodeling and reduce plasma B-type natriuretic peptide (BNP), a surrogate biomarker of heart failure. However, the relationship between reverse LV remodeling and plasma BNP changes after RMA is poorly defined. We explored the main hemodynamic factors contributing to change in plasma BNP after RMA in patients with functional mitral regurgitation (MR).

Restrictive mitral annuloplasty with or without surgical ventricular restoration in ischemic dilated cardiomyopathy with severe mitral regurgitation.

Background: We assessed changes in left ventricular (LV) volume and function and in regional myocardial wall stress in noninfarcted segments after restrictive mitral annuloplasty (RMA) with or without surgical ventricular restoration (SVR).

Methods And Results: Thirty-nine patients with ischemic cardiomyopathy (ejection fraction ≤ 0.35) and severe mitral regurgitation (≥ 3) were studied before and 2.

Collagenous colitis appeared after 6-year administration of lansoprazole.

Collagenous colitis (CC) is one of the causes of undefined watery diarrhea, which is histologically accompanied by thickening of the subepithelial collagen layer. CC associated with lansoprazole normally occurs within several weeks after initial administration, but no case presenting after long-term administration of lansoprazole has yet been reported. A 77-year-old male with 6-year history of administration of lansoprazole complained of watery diarrhea and weight loss.

Reduction in adverse reactions to platelets by the removal of plasma supernatant and resuspension in a new additive solution (M-sol).

Background: Leukodepletion reduces but does not eliminate adverse reactions to platelet concentrate (PC). As an alternative strategy, plasma reduction or washing of platelets should be considered. However, the efficacy of this strategy is still unclear.

Tilt control in optical tweezers.

Laser trapping of micrometer-sized objects floating in water is investigated through the use of a tilted laser beam. With a change in the tilt direction, the orientation of the trapped object can be easily controlled when the object has an asymmetric body or nonuniform refractive index, such as nanowires, living cells, and so on. The method enables efficient orientation control under laser trapping through a simple setup.

Pleiotrophic functions of Epstein-Barr virus nuclear antigen-1 (EBNA-1) and oriP differentially contribute to the efficiency of transfection/expression of exogenous gene in mammalian cells.

The EBNA1 gene and oriP sequence, originally derived from the EBV genome, provide plasmid vectors with artificial chromosome (AC)-like characteristics, including cytoplasm-to-nuclear transport, nuclear retention, replication and segregation of the DNA, while transcriptional up-regulation has been suggested as another activity of the EBNA1/oriP. Transfection as well as expression rates of various nonviral delivery vehicles are highly improved by inserting these genetic elements into plasmid DNA constructs. Here we differentially analyzed the contribution of each function of the EBNA1/oriP to the efficacy of electroporation-mediated genetic delivery and expression in mammalian cells.

In situ analysis of the higher-order genome structure in a single Escherichia coli cell.

We developed a novel method for the in situ analysis of the higher-order structure of an individual genome from a single Escherichia coli cell using laser tweezers. Initially, condensed DNA was stably grasped by a laser without any chemical modification and without physical attachment to an artificial object such as micro-plastic beads. Under optical transport, the trapped genome gradually unfolded in solution due to viscous friction.

Hyaluronic acid and its derivative as a multi-functional gene expression enhancer: protection from non-specific interactions, adhesion to targeted cells, and transcriptional activation.

Hyaluronic acid (HA), a natural anionic mucopolysaccharide, can be deposited onto the cationic surface of DNA/polyethyleneimine (PEI) complexes to recharge the surface potential and reduce nonspecific interactions with proteins. HA can also be used as a ligand to target specific cell receptors. Furthermore, HA-coating enhanced the transcriptional activity of the plasmid/PEI complexes, probably by loosening the tight binding between DNA and PEI, which facilitated the approach of transcription factors.

Enhancement and inhibition of DNA transcriptional activity by spermine: a marked difference between linear and circular templates.

We compared the transcriptional activities of the circular and linear forms of short (4kbp) and giant (106kbp) DNA molecules in the presence of a polyamine, spermine (4+). With an increase in the spermine concentration, transcriptional activity was enhanced, followed by an inhibitory effect, and complete inhibition was observed in the sole case of long, linear templates. A difference between the transcriptional properties of circular and linear conformations is found for giant DNA molecules.

Folding transition into a loosely collapsed state in plasmid DNA as revealed by single-molecule observation.

The conformational transition of a plasmid DNA, pGEG.GL3 (12.5 kbp, circular), induced by spermine(4+) was studied through the observation of individual DNA by fluorescence microscopy.

NTP concentration switches transcriptional activity by changing the large-scale structure of DNA.

It is becoming clearer that genetic activity is closely associated with the intracellular energy state. However, the mechanisms of this association are still unclear. In this study, we focused on large-scale changes in the structure of DNA to examine the effect of the NTP concentration on the transcription reaction with T7 RNA polymerase and compared the results with long duplex DNA to those with a short persistent-length(1) fragment.