cMyBPC phosphorylation modulates the effect of omecamtiv mecarbil on myocardial force generation

Omecamtiv mecarbil (OM), a direct myosin motor activator, is currently being tested as a therapeutic replacement for conventional inotropes in heart failure (HF) patients. It is known that HF patients exhibit dysregulated β-adrenergic signaling and decreased cardiac myosin-binding protein C (cMyBPC) phosphorylation, a critical modulator of myocardial force generation. However, the functional effects of OM in conditions of altered cMyBPC phosphorylation have not been established. Here, we tested the effects of OM on force generation and cross-bridge (XB) kinetics using murine myocardial preparations isolated from wild-type (WT) hearts and from hearts expressing S273A, S282A, and S302A substitutions (SA) in the M domain, between the C1 and C2 domains of cMyBPC, which cannot be phosphorylated. At submaximal Ca²⁺ activations, OM-mediated force enhancements were less pronounced in SA than in WT myocardial preparations. Additionally, SA myocardial preparations lacked the dose-dependent increases in force that were observed in WT myocardial preparations. Following OM incubation, the basal differences in the rate of XB detachment (k_rel) between WT and SA myocardial preparations were abolished, suggesting that OM differentially affects the XB behavior when cMyBPC phosphorylation is reduced. Similarly, in myocardial preparations pretreated with protein kinase A to phosphorylate cMyBPC, incubation with OM significantly slowed k_rel in both the WT and SA myocardial preparations. Collectively, our data suggest there is a strong interplay between the effects of OM and XB behavior, such that it effectively uncouples the sarcomere from cMyBPC phosphorylation levels. Our findings imply that OM may significantly alter the in vivo cardiac response to β-adrenergic stimulation.     

Correction to: Sex and race differences of cerebrospinal fluid metabolites in healthy individuals

Metabolomics - Metabolomics applications to the aquaculture research are increasing steadily. The use of standardized proton nuclear magnetic resonance (1H NMR) spectroscopy can provide the...     

Computational Analysis of C-Reactive Protein for Assessment of Molecular Dynamics and Interaction Properties

Serum C-reactive protein (CRP) is used as a marker of inflammation in several diseases including autoimmune disease and cardiovascular disease. CRP, a member of the pentraxin family, is comprised of five identical subunits. CRP has diverse ligand-binding properties which depend upon different structural states of CRP. However, little is known about the molecular dynamics and interaction properties of CRP. In this study, we used SAPS, SCRATCH protein predictor, PDBsum, ConSurf, ProtScale, Drawhca, ASAView, SCide and SRide server and performed comprehensive analyses of molecular dynamics, protein–protein and residue–residue interactions of CRP. We used 1GNH.pdb file for the crystal structure of human CRP which generated two pentamers (ABCDE and FGHIJ). The number of residues involved in residue–residue interactions between A–B, B–C, C–D, D–E, F–G, G–H, H–I, I–J, A–E and F–J subunits were 12, 11, 10, 11, 12, 11, 10, 11, 10 and 10, respectively. Fifteen antiparallel β sheets were involved in β-sheet topology, and five β hairpins were involved in forming the secondary structure. Analysis of hydrophobic segment distribution revealed deviations in surface hydrophobicity at different cavities present in CRP. Approximately 33 % of all residues were involved in the stabilization centers. We show that the bioinformatics tools can provide a rapid method to predict molecular dynamics and interaction properties of CRP. Our prediction of molecular dynamics and interaction properties of CRP combined with the modeling data based on the known 3D structure of CRP is helpful in designing stable forms of CRP mutants for structure–function studies of CRP and may facilitate in silico drug design for therapeutic targeting of CRP.     

Continuous biosorption of cadmium by Moringa olefera in a packed column

The biosorption of Cd(II) by Moringa oleifera using a batch system and a continuous up flow mode in a fixed bed column was studied. Batch adsorption experiments were performed as a function of pH, biosorbent dose, contact time, volume of the solution, and initial metal concentration. The adsorption isotherms obtained fitted well into the Freundlich and Langmuir isotherms. The dynamic removal of cadmium by powdered seed of the Moringa oleifera was studied in a packed column. The effect of bed height (4 and 8 cm) and flow rate (2 and 5mL/min) on biosorption process was investigated and the experimental breakthrough curves were obtained. Results showed that by increasing the bed height and decreasing the flow rate, the breakthrough and exhaustion times increased. The break-through time was considered as a measure of the column performance. The maximum break-through time of 320 min was achieved at the operating condition of 2 mL/min influent flow rate and bed height of 8 cm.     

Synthesis and Properties of 2′-O-Methylribonucleotide Methylphosphonate Containing Chimeric Oligonucleotides

Abstract

2′-O-methylribonucleoside methylphosphonamidites are synthesized and incorporated into oligonucleotides to obtain chimeric antisense oligonucleotides. The resulting oligonucleotide binds to their target RNA/DNA sequences efficiently and stable in a medium containing bovine serum.     

Destabilization of DNA Guanine Quadruplex Structure by Foldback Triplex-Forming Oligodeoxynucleotides

Abstract

An oligodeoxynucleotide designed to bind to a single stranded guanine rich DNA sequence through Watson-Crick followed by Hoogsteen hydrogen bonds was found to destabilize quadruplex structure formed by the target sequence. However, the conventional antisense and antigene oligonucleotides were unable to destabilize the same quadruplex structure.     

The Use of Vacuum Erection Devices in Erectile Dysfunction After Radical Prostatectomy

The risk of postoperative erectile dysfunction (ED) following radical prostatectomy (RP) is reported to be between 14% and 89%. With an increase in the detection of prostate cancer in younger men, there is a greater emphasis on the appropriate management of ED following RP. A number of options are available to manage ED after RP, including phosphodiesterase-5 inhibitors, intracorporeal injections, intraurethral alprostadil, and vacuum erection devices (VEDs). Penile rehabilitation programs are increasingly used to facilitate the return of natural postoperative erections; the VED is an ideal therapy given that it increases blood flow and oxygenation to the corpora to reverse the changes that result in ED after RP.Key words: Erectile dysfunction, Radical prostatectomy, Vacuum erection device, Penile rehabilitationProstate cancer is the most common cancer in men over the age of 50 years.¹ When patients undergo a radical prostatectomy (RP), there is a risk of postoperative erectile dysfunction (ED). The incidence of ED following RP has been reported to be between 14% and 89%.² With an increase in the detection of prostate cancer in younger men, there is a greater emphasis on the appropriate management of ED after RP. With an early diagnosis of prostate cancer, there is an increase in the rate of RP in younger men and the importance of ED as a quality-of-life issue has subsequently increased.² There are a number of options available to manage ED after RP, including phosphodiesterase-5 (PDE-5) inhibitors, intracorporeal injections, intraurethral alprostadil, and vacuum erection devices (VEDs). Despite highly reported satisfaction and efficacy with VEDs, there is a move by some medical practitioners away from VEDs due to cost. But what evidence is there for VED success after prostatectomy and what role do VEDs have in penile rehabilitation after ED? We present current evidence and provide our recommendations based on the latest literature.     

Oligonucleotides Containing Acyclic Nucleoside Analogues with Carbamate Internucleoside Linkages

Abstract

Synthesis of 2′-deoxy-2′,3′-secothymidine t and its dimer t?t, where the two 2′-deoxy-2′,3′-secothymidine t units are connected via a carbamate, ?=3′-NH-CO-O-5′, internucleoside linkage has been achieved. These building blocks were protected in the 5′-position, converted into their phosphoramidites, or attached onto CPG, and then used for “chimeric oligonucleotide” synthesis.     

Mixed-Backbone Oligonucleotides Containing Phosphorothioate and Methylphosphonate Linkages as Second Generation Antisense Oligonucleotide

Abstract

Antisense oligonucleotides are being studied as novel therapeutic agents. To further improve the properties of antisense oligonucleotides, we have synthesized phosphorothioate oligonucleotides containing methylphosphonate linkages at the 5′-end, the 3′-end, or in the center, and have evaluated the impact of these linkages on the biophysical properties, biological properties, and some of the safety parameters.     

Controlled Release of Ropinirole Hydrochloride from a Multiple Barrier Layer Tablet Dosage Form: Effect of Polymer Type on Pharmacokinetics and IVIVC

The purpose of the present study was to control in vitro burst effect of the highly water-soluble drug, ropinirole hydrochloride to reduce in vivo dose dumping and to establish in vitro–in vivo correlation. The pharmacokinetics of two entirely different tablet formulation technologies is also explored in this study. For pharmacokinetics study, FDA recommends at least 10% difference in drug release for formulations to be studied but here a different approach was adopted. The formulations F8A and F9A having similar dissolution profiles among themselves and with Requip® XL™ (f₂ value 72, 77, 71 respectively) were evaluated. The C_max of formulation F8A comprising hypromellose 100,000 cP was 1005.16 pg/ml as compared to 973.70 pg/ml of formulation F9A comprising hypromellose 4000 cP irrespective of T_max of 5 and 5.75 h, respectively. The difference in release and extent of absorption in vivo was due to synergistic effect of complex RH release mechanism; however, AUC_0–t and AUC_0–∞ values were comparable. The level A correlation using the Wagner–Nelson method supported the findings where R² was 0.7597 and 0.9675 respectively for formulation F8A and F9A. Thus, in vivo studies are required for proving the therapeutic equivalency of different formulation technologies even though f₂ ≥ 50. The technology was demonstrated effectively at industrial manufacturing scale of 200,000 tablets.KEY WORDS: controlled release polymer, in vitro–in vivo correlation (IVIVC), multiple barrier layer tablets, pharmacokinetics, ropinirole hydrochloride (RH)