Intrinsically disordered proteins play important roles in cell signalling, transcription, translation and cell cycle regulation. Although they lack stable tertiary structure, many intrinsically disordered proteins undergo disorder-to-order transitions upon binding to partners. Similarly, several folded proteins use regulated order-to-disorder transitions to mediate biological function. In principle, the function of intrinsically disordered proteins may be controlled by post-translational modifications that lead to structural changes such as folding, although this has not been observed. Here we show that multisite phosphorylation induces folding of the intrinsically disordered 4E-BP2, the major neural isoform of the family of three mammalian proteins that bind eIF4E and suppress cap-dependent translation initiation. In its non-phosphorylated state, 4E-BP2 interacts tightly with eIF4E using both a canonical YXXXXLΦ motif (starting at Y54) that undergoes a disorder-to-helix transition upon binding and a dynamic secondary binding site. We demonstrate that phosphorylation at T37 and T46 induces folding of residues P18-R62 of 4E-BP2 into a four-stranded β-domain that sequesters the helical YXXXXLΦ motif into a partly buried β-strand, blocking its accessibility to eIF4E. The folded state of pT37pT46 4E-BP2 is weakly stable, decreasing affinity by 100-fold and leading to an order-to-disorder transition upon binding to eIF4E, whereas fully phosphorylated 4E-BP2 is more stable, decreasing affinity by a factor of approximately 4,000. These results highlight stabilization of a phosphorylation-induced fold as the essential mechanism for phospho-regulation of the 4E-BP:eIF4E interaction and exemplify a new mode of biological regulation mediated by intrinsically disordered proteins.
Hypoglycemia was common among hospitalized patients receiving insulin and, while a direct causal relationship cannot be assumed, was associated with an increased risk of inpatient mortality and increased length of hospital stay. Hypoglycemia is an undesirable event and efforts to minimize in-hospital hypoglycemic events are warranted across the spectrum of hospitalized patients.
Aliskiren showed a similar pharmacokinetic profile in healthy volunteers and patients with type 2 diabetes, and administration of a single oral 300 mg dose of aliskiren was well tolerated by both patients and healthy volunteers. The pharmacodynamic effects of aliskiren were also similar in healthy volunteers and diabetic patients, with sustained inhibition of renin system activity observed for at least 24 hours after dosing.
AimTo assess the factors associated with antihyperglycaemic medication initiation in UK patients with newly diagnosed type 2 diabetes.MethodsIn a retrospective cohort study, patients with newly diagnosed type 2 diabetes were identified during the index period of 2003-2005. Eligible patients were ≥ 30 years old at the date of the first observed diabetes diagnosis (referred to as index date) and had at least 2 years of follow-up medical history (N = 9,158). Initiation of antihyperglycaemic medication (i.e., treatment) was assessed in the 2-year period following the index date. Adjusted Cox regression models were used to examine the association between time to medication initiation and patient age and other factors.ResultsMean (SD) HbA1c at diagnosis was 8.1% (2.3). Overall, 51% of patients initiated antihyperglycaemic medication within 2 years (65%, 55%, 46% and 40% for patients in the 30- < 45, 45- < 65, 65- < 75, 75+ age groups, respectively). Among the treated patients, median (25th, 75th percentile) time to treatment initiation was 63 (8, 257) days. Of the patients with HbA1c ≥ 7.5% at diagnosis, 87% initiated treatment within 2 years. These patients with a higher HbA1c also had shorter time to treatment initiation (adjusted hazard ratio (HR) = 2.44 [95% confidence interval (CI): 1.61, 3.70]; p < 0.0001). Increasing age (in years) was negatively associated with time to treatment initiation (HR = 0.98 [95% CI: 0.97, 0.99]; p < 0.001). Factors significantly associated with shorter time to treatment initiation included female gender and use of cardiovascular medications at baseline or initiated during follow up.ConclusionsIn this UK cohort of patients with newly diagnosed type 2 diabetes, only 51% had antihyperglycaemic medication initiated over a 2-year period following diagnosis. Older patients were significantly less likely to have been prescribed antihyperglycaemic medications. Elevated HbA1c was the strongest factor associated with initiating antihyperglycaemic medication in these patients.
Précis: Modeling of visual field and pharmacy data (Kaiser Permanente, 2001 to 2014) from open-angle/pseudoexfoliation glaucoma patients in clinical practice indicated a significant inverse association between the level of medication adherence and rate of visual field progression. Purpose: The aim was to quantify the effect of nonadherence to topical hypotensive medication on glaucomatous visual field progression in clinical practice. Methods: Retrospective analysis of combined visual field and pharmacy data from Kaiser Permanente Southern California’s HealthConnect electronic health record database. Patients with a diagnosis of primary open-angle glaucoma or pseudoexfoliation glaucoma (2001 to 2011) and ≥3 subsequent visual field tests of the same Swedish Interactive Threshold Algorithm type were followed up from first medication fill to final visual field test. Medication adherence (proportion of days covered) was estimated from pharmacy refill data. A conditional growth model was used to estimate the effect of adherence level in modifying the progression of mean deviation over time after adjusting for potential confounders, including age, sex, race/ethnicity, baseline glaucoma severity, and comorbidity. Results: In total, 6343 eligible patients were included in the study and followed for (mean) 5.8 years; average treatment adherence during follow-up was 73%. After controlling for confounders and the interaction between time and baseline disease severity, the model indicated that mean deviation progression was significantly ( P =0.006) reduced by 0.006 dB per year for each 10% (absolute) increase in adherence. Model estimates of time to glaucoma progression (mean deviation change −3 dB from baseline) were 8.3 and 9.3 years for patients with adherence levels of 20% and 80%, respectively. Conclusions: Improving patient adherence to topical glaucoma medication may result in slower deterioration in visual function over time.
The postictal state following seizures is characterized by impaired consciousness and has a major negative impact on individuals with epilepsy. Previous work in disorders of consciousness including the postictal state suggests that bilateral deep brain stimulation (DBS) of the thalamic intralaminar central lateral nucleus (CL) may improve level of arousal. We tested the effects of postictal thalamic CL DBS in a rat model of secondarily generalized seizures elicited by electrical hippocampal stimulation. Thalamic CL DBS was delivered at 100 Hz during the postictal period in 21 female rats while measuring cortical electrophysiology and behavior. The postictal period was characterized by frontal cortical slow waves, like other states of depressed consciousness. In addition, rats exhibited severely impaired responses on two different behavioral tasks in the postictal state. Thalamic CL stimulation prevented postictal cortical slow wave activity but produced only modest behavioral improvement on a spontaneous licking sucrose reward task. We therefore also tested responses using a lever-press shock escape/avoidance (E/A) task. Rats achieved high success rates responding to the sound warning on the E/A task even during natural slow wave sleep but were severely impaired in the postictal state. Unlike the spontaneous licking task, thalamic CL DBS during the E/A task produced a marked improvement in behavior, with significant increases in lever-press shock avoidance with DBS compared with sham controls. These findings support the idea that DBS of subcortical arousal structures may be a novel therapeutic strategy benefitting patients with medically and surgically refractory epilepsy.
AimTo estimate the rate of adherence to oral antihyperglycemic monotherapy for patients with type 2 diabetes in the US and describe factors associated with adherence in these patients.Materials and methodsIn this retrospective cohort analysis, patients aged 18 years or older with a type 2 diabetes diagnosis received between 1 January 2007 and 31 March 2010 were identified using a large US-based health care claims database. The index date was defined as the date of the first prescription for oral antihyperglycemic monotherapy during this period. Patients had to have continuous enrollment in the claims database for 12 months before and after the index date. Adherence was assessed using proportion of days covered (PDC) and an adjusted logistic regression analysis was performed to evaluate factors associated with adherence (PDC ≥80%).ResultsOf the 133,449 eligible patients, the mean age was 61 years and 51% were men. Mean PDC was 75% and the proportion of patients adherent to oral antihyperglycemic monotherapy was 59%. Both mean PDC and PDC ≥80% increased with increasing age and the number of concomitant medications, and were slightly higher in men compared to women. Results from the logistic regression demonstrate an increased likelihood of non-adherence for patients who were younger, new to therapy, on a twice-daily dose, female, or on fewer than three concomitant medications compared to their reference groups. Higher average daily out-of-pocket pharmacy expense was also associated with an increased likelihood of non-adherence. All results were statistically significant (P<0.05).ConclusionPatient characteristics, treatment regimens, and out-of-pocket expenses were associated with adherence to oral antihyperglycemic monotherapy in our study.
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