Engineering Escherichia coli for efficient conversion of glucose to pyruvate

Escherichia coli TC44, a derivative of W3110, was engineered for the production of pyruvate from glucose by combining mutations to minimize ATP yield, cell growth, and CO2 production (DeltaatpFH DeltaadhE DeltasucA) with mutations that eliminate acetate production [poxB::FRT (FLP recognition target) DeltaackA] and fermentation products (DeltafocA-pflB DeltafrdBC DeltaldhA DeltaadhE). In mineral salts medium containing glucose as the sole carbon source, strain TC44(DeltafocA-pflB DeltafrdBC DeltaldhA DeltaatpFH DeltaadhE DeltasucA poxB::FRT DeltaackA) converted glucose to pyruvate with a yield of 0.75 g of pyruvate per g of glucose (77.9% of theoretical yield; 1.2 g of pyruvate liters(-1).h(-1)). A maximum of 749 mM pyruvate was produced with excess glucose. Glycolytic flux was >50% faster for TC44 producing pyruvate than for the wild-type W3110 during fully aerobic metabolism. The tolerance of E. coli to such drastic changes in metabolic flow and energy production implies considerable elasticity in permitted pool sizes for key metabolic intermediates such as pyruvate and acetyl-CoA. In strain TC44, pyruvate yield, pyruvate titer, and the rate of pyruvate production in mineral salts medium were equivalent or better than previously reported for other biocatalysts (yeast and bacteria) requiring complex vitamin feeding strategies and complex nutrients. TC44 offers the potential to improve the economics of pyruvate production by reducing the costs of materials, product purification, and waste disposal.     

Chronic Leg Ulceration Associated with Polycythemia Vera Responding to Ruxolitinib (Jakafi®)

We present the case of a 63-year-old white male with bilateral chronic leg ulcers due to polycythemia vera and hydroxyurea therapy who demonstrated dramatic healing of his wounds in response to ruxolitinib (Jakafi^®, Novartis), a novel Janus kinase-1 and -2 inhibitor. This patient's wound had previously been refractory to multiple surgical interventions and immunosuppression. After the initiation of ruxolitinib, the patient underwent successful split-thickness skin grafting, with resultant healing of his wounds. He was stable without prednisone and other immunosuppressant therapy and had healed at 6 months. Ruxolitinib therapy could represent a novel option for patients who develop persistent inflammatory wounds in the setting of polycythemia vera and hydroxyurea therapy.     

Living donor liver transplantation for biliary atresia – An Indian experience

LT has played a significant role in improving the outcome of children with BA. We review our five‐yr experience of LDLT for children with BA. Records of all children who underwent LDLT in our institution over a five‐yr period (August 2010–June 2015) were reviewed and those with a primary diagnosis of BA were selected for our study. Data were extracted from a prospectively maintained database. Additional data were collected by review of case notes and imaging studies. Analysis was carried out using standard statistical means. One hundred and thirty‐two children underwent LDLT at our center over the study period, of which 58 children (31 females) had a primary diagnosis of BA. Thirty‐three (56.9%) children had undergone a prior KPE and 25 (43.1%) had a primary LT. Thirty‐four children had at least one post‐op complication, of which 13 had minor complications (Clavien grades I and II) and 21 had major complications (Clavien grade >II). Thirty‐day survival was 96.6% and one‐yr survival was 91.4%. Univariate analysis of variables comparing children who did and did not have a KPE prior to LT showed that age at LT, weight at LT, PELD, and GRWR were significantly different. LDLT provides excellent outcomes in children with BA. Primary LDLT and LT after KPE provide equivalent results, although the former is technically more challenging as the child is younger.     

Determination of anti-inflammatory activities of standardised preparations of plant- and mushroom-based foods

Purpose

Chronic inflammatory processes contribute to the pathogenesis of many age-related diseases. In search of anti-inflammatory foods, we have systematically screened a variety of common dietary plants and mushrooms for their anti-inflammatory activity.

Methods

A selection of 115 samples was prepared by a generic food-compatible processing method involving heating. These products were tested for their anti-inflammatory activity in murine N11 microglia and RAW 264.7 macrophages, using nitric oxide (NO) and tumour necrosis factor-α (TNF-α) as pro-inflammatory readouts.

Results

Ten food samples including lime zest, English breakfast tea, honey-brown mushroom, button mushroom, oyster mushroom, cinnamon and cloves inhibited NO production in N11 microglia, with IC₅₀ values below 0.5 mg/ml. The most active samples were onion, oregano and red sweet potato, exhibiting IC₅₀ values below 0.1 mg/ml. When these ten food preparations were retested in RAW 264.7 macrophages, they all inhibited NO production similar to the results obtained in N11 microglia. In addition, English breakfast tea leaves, oyster mushroom, onion, cinnamon and button mushroom preparations suppressed TNF-α production, exhibiting IC₅₀ values below 0.5 mg/ml in RAW 264.7 macrophages.

Conclusion

In summary, anti-inflammatory activity in these food samples survived ‘cooking’. Provided that individual bioavailability allows active compounds to reach therapeutic levels in target tissues, these foods may be useful in limiting inflammation in a variety of age-related inflammatory diseases. Furthermore, these foods could be a source for the discovery of novel anti-inflammatory drugs.