Hypoplastic Circumflex Aorta With Anomalous Left Pulmonary Artery: Uncrossing Operation in a Neonate.

Circumflex aortic arch with coarctation and anomalous origin of the left pulmonary artery from the aorta are rare cardiovascular anomalies. These conditions can lead to early pulmonary hypertension and challenging management. Early diagnosis and surgical intervention are beneficial for optimal outcome. We present a case where both anomalies coexisted and were repaired with aortic uncrossing, arch augmentation, and reimplantation of the left pulmonary artery. To our knowledge, this is the first documented instance of these anomalies coexisting and being repaired in the neonatal period.

Massive Embolism: Knife versus PCI.

Pulmonary embolism is the third most common cardiovascular syndrome with an estimated up to 25% of patients presenting with sudden death. For those who survive, a mainstay of management for patients with hemodynamic stability is anticoagulation; however, recommendations and options are rapidly changing for patients with submassive or massive pulmonary embolism with hemodynamic instability. Catheter-based and surgical approaches offer efficacious management options for unstable patients or patients with contraindications to anticoagulation; however, both approaches have inherent benefits and risk. This article seeks to offer a brief review on the recommendations and options for management of pulmonary embolism from both surgical and catheter-based perspectives.

Modular optimization in metabolic engineering.

There is an increasing demand for bioproducts produced by metabolically engineered microbes, such as pharmaceuticals, biofuels, biochemicals and other high value compounds. In order to meet this demand, modular optimization, the optimizing of subsections instead of the whole system, has been adopted to engineer cells to overproduce products. Research into modularity has focused on traditional approaches such as DNA, RNA, and protein-level modularity of intercellular machinery, by optimizing metabolic pathways for enhanced production. While research into these traditional approaches continues, limitations such as scale-up and time cost hold them back from wider use, while at the same time there is a shift to more novel methods, such as moving from episomal expression to chromosomal integration. Recently, nontraditional approaches such as co-culture systems and cell-free metabolic engineering (CFME) are being investigated for modular optimization. Co-culture modularity looks to optimally divide the metabolic burden between different hosts. CFME seeks to modularly optimize metabolic pathways in vitro, both speeding up the design of such systems and eliminating the issues associated with live hosts. In this review we will examine both traditional and nontraditional approaches for modular optimization, examining recent developments and discussing issues and emerging solutions for future research in metabolic engineering.

Cell-free production of isobutanol: A completely immobilized system.

A completely immobilized cell-free enzyme reaction system was used to convert ketoisovaleric acid to isobutanol, a desirable biofuel, with a molar yield of 43% and a titer of 2 g/L, which are comparable to high performing in vivo systems (e.g. 41% and 5.4 g/L, respectively, for Clostridium thermocellum). The approach utilizes, for the first time, a series of previously reported enzyme mutants that either overproduce the product or are more stable when compared with their wild type. The selected enzyme variants include keto-acid decarboxylase attached to a maltose binding protein, alcohol dehydrogenase, and formate dehydrogenase. These enzymes were screened for thermal, pH, and product stability to choose optima for this system which were pH 7.4 and 35 °C. This system is designed to address well-known limitations of in vivo systems such as low product concentrations due to product feedback inhibition, instability of cells, and lack of economic product recovery.