Dysregulation of Endothelial Nitric Oxide Synthase Does Not Depend on Hemodynamic Alterations in Bicuspid Aortic Valve Aortopathy.

Background Bicuspid aortic valves (BAVs) predispose to ascending aortic aneurysm. Turbulent blood flow and genetic factors have been proposed as underlying mechanisms. Endothelial nitric oxide synthase (eNOS) has been implicated in BAV aortopathy, and its expression is regulated by wall shear stress.

Total synthesis of Escherichia coli with a recoded genome.

Nature uses 64 codons to encode the synthesis of proteins from the genome, and chooses 1 sense codon-out of up to 6 synonyms-to encode each amino acid. Synonymous codon choice has diverse and important roles, and many synonymous substitutions are detrimental. Here we demonstrate that the number of codons used to encode the canonical amino acids can be reduced, through the genome-wide substitution of target codons by defined synonyms.

Controlling orthogonal ribosome subunit interactions enables evolution of new function.

Orthogonal ribosomes are unnatural ribosomes that are directed towards orthogonal messenger RNAs in Escherichia coli, through an altered version of the 16S ribosomal RNA of the small subunit. Directed evolution of orthogonal ribosomes has provided access to new ribosomal function, and the evolved orthogonal ribosomes have enabled the encoding of multiple non-canonical amino acids into proteins. The original orthogonal ribosomes shared the pool of 23S ribosomal RNAs, contained in the large subunit, with endogenous ribosomes.

Detecting RNA base methylations in single cells by in situ hybridization.

Methylated bases in tRNA, rRNA and mRNA control a variety of cellular processes, including protein synthesis, antimicrobial resistance and gene expression. Currently, bulk methods that report the average methylation state of ~10-10 cells are used to detect these modifications, obscuring potentially important biological information. Here, we use in situ hybridization of Molecular Beacons for single-cell detection of three methylations (mA, mG and mU) that destabilize Watson-Crick base pairs.

Biosynthesis and genetic encoding of phosphothreonine through parallel selection and deep sequencing.

The phosphorylation of threonine residues in proteins regulates diverse processes in eukaryotic cells, and thousands of threonine phosphorylations have been identified. An understanding of how threonine phosphorylation regulates biological function will be accelerated by general methods to biosynthesize defined phosphoproteins. Here we describe a rapid approach for directly discovering aminoacyl-tRNA synthetase-tRNA pairs that selectively incorporate non-natural amino acids into proteins; our method uses parallel positive selections combined with deep sequencing and statistical analysis and enables the direct, scalable discovery of aminoacyl-tRNA synthetase-tRNA pairs with mutually orthogonal substrate specificity.

Physical and mental recovery after conventional aortic valve surgery.

Objective: Physical and mental recovery are important factors to consider in the treatment of aortic valve disease, and the process of recovery is not well known. We investigated the course of physical and mental recovery directly after conventional aortic valve surgery.

Methods: In a longitudinal study, 60 patients undergoing elective aortic valve surgery were studied preoperatively and at intervals of 4 weeks after aortic valve surgery.

Sinus Plication to Improve Valve Configuration in Bicuspid Aortic Valve Repair-Early Results.

Background: Previous experience with repair of the regurgitant bicuspid aortic valve (BAV) has shown a strong influence of commissural orientation on repair durability. We have modified commissural orientation by asymmetric plication of the fused sinuses. We analyzed the results of the modified technique.

Ribosome Subunit Stapling for Orthogonal Translation in .

The creation of orthogonal large and small ribosomal subunits, which interact with each other but not with endogenous ribosomal subunits, would extend our capacity to create new functions in the ribosome by making the large subunit evolvable. To this end, we rationally designed a ribosomal RNA that covalently links the ribosome subunits via an RNA staple. The stapled ribosome is directed to an orthogonal mRNA, allowing the introduction of mutations into the large subunit that reduce orthogonal translation, but have minimal effects on cell growth.

Vasopressin as Therapy During Nonocclusive Mesenteric Ischemia.

Background: Vasopressin is used as an adjunct to norepinephrine to support blood pressure in vasodilatory shock after cardiopulmonary bypass (CPB). In this study, we report our observation of vasopressin treatment in 11 patients with nonocclusive mesenteric ischemia (NOMI).

Methods: In an observational cohort study, 78 patients were studied after having been treated for NOMI with intraarterial iloprost infusion after elective cardiac operation.

Ribosome Subunit Stapling for Orthogonal Translation in E. coli.

The creation of orthogonal large and small ribosomal subunits, which interact with each other but not with endogenous ribosomal subunits, would extend our capacity to create new functions in the ribosome by making the large subunit evolvable. To this end, we rationally designed a ribosomal RNA that covalently links the ribosome subunits via an RNA staple. The stapled ribosome is directed to an orthogonal mRNA, allowing the introduction of mutations into the large subunit that reduce orthogonal translation, but have minimal effects on cell growth.

[Quality of life or life expectancy? Criteria and sources of information in the decision-making of patients undergoing aortic valve surgery].

Objectives: Physicians are expected to involve patients adequately in the decision-making process prior to surgery. To this end, it is essential to have knowledge about the potential reasons for such a decision. In this study we investigated which information sources and decision criteria are important to patients prior to aortic valve surgery.

Elevated endothelin-1 level is a risk factor for nonocclusive mesenteric ischemia.

Objective: Nonocclusive mesenteric ischemia may occur after cardiac surgery, commonly in conjunction with the use of cardiopulmonary bypass. Some evidence suggests that endothelin-1 serum levels are increased in patients with mesenteric ischemia, but the association of endothelin-1 and nonocclusive mesenteric ischemia has not been studied. The objective was to investigate whether elevated levels of endothelin-1 could be found in patients exhibiting nonocclusive mesenteric ischemia.

Reexamining remodeling.

Objective: Root remodeling was proposed as valve-preserving root replacement to treat patients with aortic regurgitation and root aneurysm. The objective of this retrospective study was to review 18 years of experience with root remodeling and to identify predictors of valve durability.

Methods: Between October 1995 and December 2013, root remodeling was performed in 747 patients.

Cost of illness due to typhoid Fever in pemba, zanzibar, East Africa.

The aim of this study was to estimate the economic burden of typhoid fever in Pemba, Zanzibar, East Africa. This study was an incidence-based cost-of-illness analysis from a societal perspective. It covered new episodes of blood culture-confirmed typhoid fever in patients presenting at the outpatient or inpatient departments of three district hospitals between May 2010 and December 2010.

Efficient multisite unnatural amino acid incorporation in mammalian cells via optimized pyrrolysyl tRNA synthetase/tRNA expression and engineered eRF1.

The efficient, site-specific introduction of unnatural amino acids into proteins in mammalian cells is an outstanding challenge in realizing the potential of genetic code expansion approaches. Addressing this challenge will allow the synthesis of modified recombinant proteins and augment emerging strategies that introduce new chemical functionalities into proteins to control and image their function with high spatial and temporal precision in cells. The efficiency of unnatural amino acid incorporation in response to the amber stop codon (UAG) in mammalian cells is commonly considered to be low.

GATA5 and endothelial nitric oxide synthase expression in the ascending aorta is related to aortic size and valve morphology.

Background: The pathogenesis of aortic dilatation in patients with congenital aortic valve anomalies is poorly understood. Recent studies suggest that alterations of gene expression may be related to ascending aortic aneurysm formation in these patients. Knockout of endothelial nitric oxide synthase (eNOS) and GATA5 is associated with bicuspid aortic valves in mice.

Identification of reference genes for quantitative RT-PCR in ascending aortic aneurysms.

Hypertension and congenital aortic valve malformations are frequent causes of ascending aortic aneurysms. The molecular mechanisms of aneurysm formation under these circumstances are not well understood. Reference genes for gene activity studies in aortic tissue that are not influenced by aortic valve morphology and its hemodynamic consequences, aortic dilatation, hypertension, or antihypertensive medication are not available so far.

Clinical and epidemiological features of typhoid fever in Pemba, Zanzibar: assessment of the performance of the WHO case definitions.

Background: The gold standard for diagnosis of typhoid fever is blood culture (BC). Because blood culture is often not available in impoverished settings it would be helpful to have alternative diagnostic approaches. We therefore investigated the usefulness of clinical signs, WHO case definition and Widal test for the diagnosis of typhoid fever.

Early results with annular support in reconstruction of the bicuspid aortic valve.

Objective: Repair of the bicuspid aortic valve may be performed in aortic regurgitation and aneurysm. Dilatation of the atrioventricular junction has been identified as a risk factor for repair failure, and we have used suture annuloplasty to correct atrioventricular junction enlargement. The objective was to compare the early results of aortic repair with and without annuloplasty.

Risk factors for nonocclusive mesenteric ischemia after elective cardiac surgery.

Objective: Nonocclusive mesenteric ischemia (NOMI) may occur after cardiopulmonary bypass. It is crucial to early identify patients who are at risk of developing this complication. The aim of this prospective study was to evaluate perioperative risk factors in a large cohort of patients undergoing elective cardiac surgery.

Cusp height in aortic valves.

Objectives: Successful aortic valve repair must normalize cusp and root dimensions. Limited information is available on the normal dimensions of human cusps, in particular the cusp height.

Methods: The cusp height was measured intraoperatively in 621 patients during aortic valve repair procedures.

Evaluation of a rapid dipstick (Crystal VC) for the diagnosis of cholera in Zanzibar and a comparison with previous studies.

Background: The gold standard for the diagnosis of cholera is stool culture, but this requires laboratory facilities and takes at least 24 hours. A rapid diagnostic test (RDT) that can be used by minimally trained staff at treatment centers could potentially improve the reporting and management of cholera outbreaks.

Methods: We evaluated the Crystal VC™ RDT under field conditions in Zanzibar in 2009.

Causes and management of aortic valve regurgitation after aortic valve reimplantation.

Objective: Recurrent aortic regurgitation can occur after valve-preserving aortic replacement. Little is known about the exact mechanisms of valve failure and the best reoperative strategies. We analyzed our experience with reoperation after aortic valve reimplantation.

The burden of invasive bacterial infections in Pemba, Zanzibar.

Background: We conducted a surveillance study to determine the leading causes of bloodstream infection in febrile patients seeking treatment at three district hospitals in Pemba Island, Zanzibar, Tanzania, an area with low malaria transmission.

Methods: All patients above two months of age presenting to hospital with fever were screened, and blood was collected for microbiologic culture and malaria testing. Bacterial sepsis and malaria crude incidence rates were calculated for a one-year period and were adjusted for study participation and diagnostic sensitivity of blood culture.

Reprogramming the genetic code: from triplet to quadruplet codes.

The genetic code of cells is near-universally triplet, and since many ribosomal mutations are lethal, changing the cellular ribosome to read nontriplet codes is challenging. Herein we review work on the incorporation of unnatural amino acids into proteins in response to quadruplet codons, and the creation of an orthogonal translation system in the cell that uses an evolved orthogonal ribosome to efficiently direct the incorporation of unnatural amino acids in response to quadruplet codons. Using this system multiple distinct unnatural amino acids have been incorporated and used to genetically program emergent properties into recombinant proteins.