Weight History in Clinical Practice: The State of the Science and Future Directions

Eliciting a weight history can provide clinically important information to aid in treatment decision‐making. This view is consistent with the life course perspective of obesity and the aim of patient‐centered care, one of six domains of health care quality. However, thus far, the value and practicality of including a weight history in the clinical assessment and treatment of patients with obesity have not been systematically explored. For these reasons, the Clinical Committee of The Obesity Society established a task force to review and assess the available evidence to address five key questions. It is concluded that weight history is an essential component of the medical history for patients presenting with overweight or obesity, and there are strong and emerging data that demonstrate the importance of life stage, duration of exposure to obesity, maximum BMI, and group‐based trajectory modeling in predicting risk for increased morbidity and mortality. Consideration of these and other patient‐specific factors may improve risk stratification and clinical decision‐making for screening, counseling, and management. Recommendations are provided for the key elements that should be included in a weight history, and several needs for future clinical research are outlined.     

Overexpression of a recombinant wild-type and His-tagged Bacillus subtilis glycine oxidase in Escherichia coli.

We have cloned the gene coding for the Bacillus subtilis glycine oxidase (GO), a new flavoprotein that oxidizes glycine and sarcosine to the corresponding alpha-keto acid, ammonia and hydrogen peroxide. By inserting the DNA encoding for GO into the multiple cloning site of the expression vector pT7.7 we produced a recombinant plasmid (pT7-GO). The pT7-GO encodes a fully active fusion protein with six additional residues at the N-terminus of GO (MARIRA). In BL21(DE3)pLysS Escherichia coli cells, and under optimal isopropyl thio-beta-D-galactoside induction conditions, soluble and active chimeric GO was expressed up to 1.14 U g(-1) of cell (and a fermentation yield of 3.82 U x L(-1) of fermentation broth). An N-terminal His-tagged protein (HisGO) was also successfully expressed in E. coli as a soluble protein and a fully active holoenzyme. HisGO represents approximately 3.9% of the total soluble protein content of the cell. The His-tagged GO was purified in a single step by nickel-chelate chromatography to a specific activity of 1.06 U x mg(-1) protein at 25 degrees C and with a yield of 98%. The characterization of the purified enzyme showed that GO is a homotetramer of approximately 180 kDa with the spectral properties typical of flavoproteins. GO exhibits good thermal stability, with a Tm of 46 degrees C after 30 min incubation; its stability is maximal in the 7.0-8.5 pH range. A comparison of amino-acid sequence and substrate specificity indicates that GO has similarities to other flavoenzymes acting on primary amines and on D-amino acids.     

D-amino Acid Oxidase as an Industrial Biocatalyst

Biocatalysis driven by D-amino acid oxidase is a significant example of the commercial production of high value-added intermediates using enzyme-based technology. The results of the most recent research on this FAD-dependent catalyst are reported here. In particular, insight is given of how in the past few years the main industrial application of this enzyme, i.e. the stereospecific bioconversion of cephalosporin C to glutaryl-7-amino cephalosporanic acid in the two-step production of 7-amino cephalosporanic acid, has been implemented by improving its production and by engineering of the biocatalyst. The set-up and the optimization of different conditions for carrying out the process under different procedures have also been updated.     

A process for bioconversion of cephalosporin C by Rhodotorula gracilis D-amino acid oxidase

Summary A process for the production (in a stirred tank reactor) of glutaryl-7-ACA from cephalosporin C using immobilized D-amino acid oxidase is described. Results so obtained under optimal conditions (1.2 mg coupled enzyme/L, pH 8.5, 2 mM cephalosporin C) point to a system which shows high conversion efficiency and a remarkable operational stability. No exogenous H₂O₂ is requested to shift the reaction equilibrium toward glutaryl-7-ACA production, nor any side product is detected. The immobilized system productivity was 54 g/day/mg of enzyme. This process represents the first reported case of a reactor successfully developed with a DAAO for bioconversion of cephalosporin C.