Citations

Purpose The purpose of this study was to determine whether an algorithm that recommended individualized changes in therapy would help providers to change therapy appropriately and improve glycemic control in their patients. Methods The algorithm recommended specific doses of oral agents and insulin based on a patient's medications and glucose or A1C levels at the time of the visit. The prospective observational study analyzed the effect of the algorithm on treatment decisions and A1C levels in patients with type 2 diabetes. Results The study included 1250 patients seen in pairs of initial and follow-up visits during a 7-month baseline and/or a subsequent 7-month algorithm period. The patients had a mean age of 62 years, body mass index of 33 kg/m2, duration of diabetes of 10 years, were 94% African American and 71% female, and had average initial A1C level of 7.7%. When the algorithm was available, providers were 45% more likely to intensify therapy when indicated (P = .005) and increased therapy by a 20% greater amount (P < .001). A1C level at follow-up was 90% more likely to be <7% in the algorithm group, even after adjusting for differences in age, sex, body mass index, race, duration of diabetes and therapy, glucose, and A1C level at the initial visit (P < .001). Conclusions Use of an algorithm that recommends patient-specific changes in diabetes medications improves both provider behavior and patient A1C levels and should allow quantitative evaluation of provider actions for that provider's patients.

MRP1 (multidrug resistance protein 1) couples ATP binding/hydrolysis at its two non-equivalent NBDs (nucleotide-binding domains) with solute transport. Some of the NBD1 mutants, such as W653C, decreased affinity for ATP at the mutated site, but increased the rate of ATP-dependent solute transport. In contrast, other NBD1 mutants, such as K684L, had decreased ATP binding and rate of solute transport. We now report that mutations of the Walker A lysine residue, K684L and K1333L, significantly alter the tertiary structure of the protein. Due to elimination of the positively charged group and conformational alterations, the K684L mutation greatly decreases the affinity for ATP at the mutated NBD1 and affects ATP binding at the unmutated NBD2. Although K684L-mutated NBD1 can bind ATP at higher concentrations, the bound nucleotide at that site is not efficiently hydrolysed. All these alterations result in decreased ATP-dependent solute transport to approx. 40% of the wild-type. In contrast, the K1333L mutation affects ATP binding and hydrolysis at the mutated NBD2 only, leading to decreased ATP-dependent solute transport to approx. 11% of the wild-type. Consistent with their relative transport activities, the amount of vincristine accumulated in cells is in the order of K1333L≥CFTR (cystic fibrosis transmembrane conductance regulator)&gt;K684L⋙wild-type MRP1. Although these mutants retain partial solute transport activities, the cells expressing them are not multidrug-resistant owing to inefficient export of the anticancer drugs by these mutants. This indicates that even partial inhibition of transport activity of MRP1 can reverse the multidrug resistance caused by this drug transporter.