Characterization of a dynamic S layer on Bacillus thuringiensis.

The surfaces of three Bacillus thuringiensis strains possess an S layer composed of linear arrays of small particles arranged with p2 symmetry and with a = 8.5 nm, b = 7.2 nm, and gamma = 73 degrees. Platinum shadows of whole cells and S-layer fragments revealed the outer surface of the array to be smooth and the inner surface to be corrugated. Treatment with 2 M guanidine hydrochloride at pH 2.5 to 4 best removed the S layer for chemical characterization; it was a relatively hydrophilic 91.4-kilodalton protein with a pI of 5, no detectable carbohydrate, cysteine, methionine or tryptophan, and 21.2% nonpolar residues. No N-terminal homology with other S-layer proteins was evident. Antibody labeling experiments confirmed that the amount of S layer was proportional to the growth phase in broth cultures. Late-exponential- and stationary-growth-phase cells typically sloughed off fragments of S layer, and this may be the result of wall turnover. Indigenous autolytic activity in isolated walls rapidly digested the wall fabric, liberating soluble S-layer protein. At the same time, proteases frequently reduced the molecular weight of the 91.4-kilodalton protein, but these polypeptides could still be identified as S-layer components by immunoblotting. As cultures were serially subcultured, the frequency of appearance of the S layer diminished, and it was eventually lost. The dynamic nature of this S layer makes it atypical of most previously identified S layers and made it unusually difficult to characterize

Short‐term cost‐utility of degludec versus glargine U100 for patients with type 2 diabetes at high risk of hypoglycaemia and cardiovascular events: A Canadian setting (DEVOTE 9)

Aims To evaluate the short‐term cost‐effectiveness of insulin degludec (degludec) vs insulin glargine 100 units/mL (glargine U100) from a Canadian public healthcare payer perspective in patients with type 2 diabetes (T2D) who are at high risk of cardiovascular events and hypoglycaemia. Materials and methods A decision analytic model was developed to estimate costs (2017 Canadian dollars [CAD]) and clinical outcomes (quality‐adjusted life years [QALYs]) with degludec vs glargine U100 over a 2‐year time horizon. The model captured first major adverse cardiovascular event, death, severe hypoglycaemia and insulin dosing. Clinical outcomes were informed by a post hoc subgroup analysis of the DEVOTE trial (NCT01959529), which compared the cardiovascular safety of degludec and glargine U100 in patients with T2D who are at high cardiovascular risk. High hypoglycaemia risk was defined as the top quartile of patients (n = 1887) based on an index of baseline hypoglycaemia risk factors. Results In patients at high hypoglycaemia risk, degludec was associated with mean cost savings (CAD 129 per patient) relative to glargine U100, driven by a lower incidence of non‐fatal myocardial infarction, non‐fatal stroke and severe hypoglycaemia, which offset the slightly higher cost of treatment with degludec. A reduced risk of cardiovascular death and severe hypoglycaemia resulted in improved effectiveness (+0.0132 QALYs) with degludec relative to glargine U100. In sensitivity analyses, changes to the vast majority of model parameters did not materially affect model outcomes. Conclusion Over a 2‐year period, degludec improved clinical outcomes at a lower cost as compared to glargine U100 in patients with T2D at high risk of cardiovascular events and hypoglycaemia