The Physical Compatibility of Clinically Used Concentrations of Diltiazem Hydrochloride With Heparin Sodium.

Acute treatment of atrial fibrillation often requires concomitant intravenous (IV) continuous infusions of unfractionated heparin and diltiazem. Concomitantly infusing these medications through the same IV line minimizes multiple IV sites. Diltiazem and heparin visual compatibility have been previously investigated but with limited drug dwell times and differing drug concentrations leading to inconsistent published results.

Considerations in the Use of Codon Optimization for Recombinant Protein Expression.

Codon optimization is a gene engineering approach that is commonly used for enhancing recombinant protein expression. This approach is possible because (1) degeneracy of the genetic code enables most amino acids to be encoded by multiple codons and (2) different mRNAs encoding the same protein can vary dramatically in the amount of protein expressed. However, because codon optimization potentially disrupts overlapping information encoded in mRNA coding regions, protein structure and function may be altered.

Codon Optimization in the Production of Recombinant Biotherapeutics: Potential Risks and Considerations.

Biotherapeutics are increasingly becoming the mainstay in the treatment of a variety of human conditions, particularly in oncology and hematology. The production of therapeutic antibodies, cytokines, and fusion proteins have markedly accelerated these fields over the past decade and are probably the major contributor to improved patient outcomes. Today, most protein therapeutics are expressed as recombinant proteins in mammalian cell lines.

Role of the Funny Current Inhibitor Ivabradine in Cardiac Pharmacotherapy: A Systematic Review.

The pharmacology, pharmacokinetics, efficacy and safety of ivabradine are reviewed. Ivabradine is an oral medication that directly and selectively inhibits the hyperpolarization-activated cyclic-nucleotide gated funny (If) current in the sinoatrial node resulting in heart rate reduction. It has a plasma elimination half-life of 6 hours and is administered twice daily.

Translation regulation by ribosomes: Increased complexity and expanded scope.

The primary function of ribosomes is to decode mRNAs into polypeptide chains; however, this description is overly simplistic. Accumulating evidence shows that ribosomes themselves can affect the relative efficiency with which various mRNAs are translated and indicates that these effects can be modulated by ribosome heterogeneity. The notion that ribosomes have regulatory capabilities was elaborated more than a decade ago in the ribosome filter hypothesis.

A cell-free expression and purification process for rapid production of protein biologics.

Cell-free protein synthesis has emerged as a powerful technology for rapid and efficient protein production. Cell-free methods are also amenable to automation and such systems have been extensively used for high-throughput protein production and screening; however, current fluidic systems are not adequate for manufacturing protein biopharmaceuticals. In this work, we report on the initial development of a fluidic process for rapid end-to-end production of recombinant protein biologics.

Base pairing between hepatitis C virus RNA and 18S rRNA is required for IRES-dependent translation initiation in vivo.

Degeneracy in eukaryotic translation initiation is evident in the initiation strategies of various viruses. Hepatitis C virus (HCV) provides an exceptional example--translation of the HCV RNA is facilitated by an internal ribosome entry site (IRES) that can autonomously bind a 40S ribosomal subunit and accurately position it at the initiation codon. This binding involves both ribosomal protein and 18S ribosomal RNA (rRNA) interactions.

A critical analysis of codon optimization in human therapeutics.

Codon optimization describes gene engineering approaches that use synonymous codon changes to increase protein production. Applications for codon optimization include recombinant protein drugs and nucleic acid therapies, including gene therapy, mRNA therapy, and DNA/RNA vaccines. However, recent reports indicate that codon optimization can affect protein conformation and function, increase immunogenicity, and reduce efficacy.

Illicit narcotic injection masquerading as acute pulmonary embolism.

A 23-year-old male presented from a nursing home with hypotension, tachycardia, diaphoresis and electrocardiographic evidence of right ventricular strain that was confirmed by echocardiography. His differential diagnosis included sepsis and pulmonary embolism. A high-resolution computed tomography scan demonstrated no pulmonary emboli but did demonstrate multiple bilateral pulmonary nodules.

Physical evidence supporting a ribosomal shunting mechanism of translation initiation for BACE1 mRNA.

In Alzheimer disease, elevated levels of the BACE1 enzyme are correlated with increased production of amyloid peptides and disease pathology. The increase in BACE1 levels is post-transcriptional and may involve altered translation efficiency. Earlier studies have indicated that translation of BACE1 mRNA is cap-dependent.

Practical considerations for the pharmacotherapy of pulmonary arterial hypertension.

Pulmonary arterial hypertension is a devastating disease. Before the 1990s, when pharmacologic treatment was finally approved, only supportive therapy was available, consisting of anticoagulation, digoxin, diuretics, and supplemental oxygen. Calcium channel blocker therapy was also an option, but only a small percentage of patients respond to it.

Analysis of rRNA processing and translation in mammalian cells using a synthetic 18S rRNA expression system.

Analysis of processing, assembly, and function of higher eukaryotic ribosomal RNA (rRNA) has been hindered by the lack of an expression system that enables rRNA to be modified and then examined functionally. Given the potential usefulness of such a system, we have developed one for mammalian 18S rRNA. We inserted a sequence tag into expansion segment 3 of mouse 18S rRNA to monitor expression and cleavage by hybridization.

Incidence of bleeding in renally impaired patients receiving incorrectly dosed eptifibatide or bivalirudin while undergoing percutaneous coronary intervention.

Background: Limited data are available regarding adverse bleeding events associated with antithrombotic agents incorrectly dosed based on renal function in patients receiving percutaneous coronary intervention (PCI).

Objective: To compare the incidence of bleeding during their hospital stay in patients with reduced renal function receiving incorrect doses of bivalirudin or eptifibatide to the incidence of correct doses, based on manufacturer recommendations; secondary objectives were to determine the incidence of correct dosing based on manufacturer recommendations and the incidence of TIMI (Thrombolysis in Myocardial Infarction) major bleeding.

Methods: A chart review over a 32-month period showed that patients with reduced renal function who received either eptifibatide or bivalirudin during PCI were evaluated for correct dosing based on manufacturer recommendations, bleeding incidence according to the TIMI criteria, and extent of bleeding according to the TIMI and GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) criteria.

Determinants of initiation codon selection during translation in mammalian cells.

Factors affecting translation of mRNA contribute to the complexity of eukaryotic proteomes. In some cases, translation of a particular mRNA can generate multiple proteins. However, the factors that determine whether ribosomes initiate translation from the first AUG codon in the transcript, from a downstream codon, or from multiple sites are not completely understood.

The 5' leader of the mRNA encoding the marek's disease virus serotype 1 pp14 protein contains an intronic internal ribosome entry site with allosteric properties.

We demonstrate the presence of a functional internal ribosome entry site (IRES) within the 5' leader (designated 5L) from a variant of bicistronic mRNAs that encode the pp14 and RLORF9 proteins from Marek's disease virus (MDV) serotype 1. Transcribed as a 1.8-kb family of immediate-early genes, the mature bicistronic mRNAs have variable 5' leader sequences due to alternative splicing or promoter usage.

Reconciling contradictory reports regarding translation of BACE1 mRNA: initiation mechanism is altered by different expression systems.

We previously showed that translation from the rat BACE1 5' leader is cap-dependent and that four AUG codons (AUG1-4) in the 5' leader were bypassed, partially or completely, depending on the cell line. Two other groups reported comparable results with human BACE1 sequences in different cell lines, although different mechanisms were postulated. In contrast, a third group working with the human sequence reported that most translation events are initiated at AUG2.

Antisense masking reveals contributions of mRNA-rRNA base pairing to translation of Gtx and FGF2 mRNAs.

We previously showed that a 9-nucleotide sequence from the 5' leader of the Gtx homeodomain mRNA facilitates translation initiation by base pairing to 18S rRNA. These earlier studies tested the Gtx element in isolation; we now assess the physiological relevance of this element in the context of two natural mRNAs that contain this sequence in their 5' leaders, Gtx itself and FGF2 (fibroblast growth factor 2). 2'-O-Methyl-modified RNA oligonucleotides were employed to block mRNA-rRNA base pairing by targeting either the Gtx-binding site in 18S rRNA or Gtx elements in recombinant mRNAs containing the Gtx or FGF2 5' leaders linked to a reporter cistron.

Analysis of ribosomal shunting during translation initiation in eukaryotic mRNAs.

In eukaryotes, translation initiation involves recruitment of ribosomal subunits at either the 5' m7G cap structure or at an internal ribosome entry site (IRES). For most mRNAs, the initiation codon is located some distance downstream, necessitating ribosomal movement to this site. Although the mechanistic details of this movement remain to be fully resolved, it appears to be nonlinear for some mRNAs (i.

The ribosome filter redux.

The ribosome filter hypothesis postulates that ribosomes are not simply translation machines but also function as regulatory elements that differentially affect or filter the translation of particular mRNAs. On the basis of new information, we take the opportunity here to review the ribosome filter hypothesis, suggest specific mechanisms of action, and discuss recent examples from the literature that support it.