Publications

CYP3A4 is an abundant and catalytically dominant human liver endoplasmic reticulum-anchored cytochrome P450 enzyme engaged in the biotransformation of endo- and xenobiotics, including >50% of clinically relevant drugs. Alterations of CYP3A4 protein turnover can influence clinically relevant drug metabolism and bioavailability and drug-drug interactions. This CYP3A4 turnover involves endoplasmic reticulum-associated degradation via the ubiquitin (Ub)-dependent 26 S proteasomal system that relies on two highly complementary E2 Ub-conjugating-E3 Ub-ligase (UBC7-gp78 and UbcH5a-C terminus of Hsc70-interacting protein (CHIP)-Hsc70-Hsp40) complexes, as well as protein kinases (PK) A and C. We have documented that CYP3A4 Ser/Thr phosphorylation (Ser(P)/Thr(P)) by PKA and/or PKC accelerates/enhances its Lys ubiquitination by either of these E2-E3 systems. Intriguingly, CYP3A4 Ser(P)/Thr(P) and ubiquitinated Lys residues reside within the cytosol-accessible surface loop and/or conformationally assembled acidic Asp/Glu clusters, leading us to propose that such post-translational Ser/Thr protein phosphorylation primes CYP3A4 for ubiquitination. Herein, this possibility was examined through various complementary approaches, including site-directed mutagenesis, chemical cross-linking, peptide mapping, and LC-MS/MS analyses. Our findings reveal that such CYP3A4 Asp/Glu/Ser(P)/Thr(P) surface clusters are indeed important for its intermolecular electrostatic interactions with each of these E2-E3 subcomponents. By imparting additional negative charge to these Asp/Glu clusters, such Ser/Thr phosphorylation would generate P450 phosphodegrons for molecular recognition by the E2-E3 complexes, thereby controlling the timing of CYP3A4 ubiquitination and endoplasmic reticulum-associated degradation. Although the importance of phosphodegrons in the CHIP targeting of its substrates is known, to our knowledge this is the first example of phosphodegron involvement in gp78-substrate recruitment, an important step in CYP3A4 proteasomal degradation.

BACKGROUND

The number of older jail inmates in poor health is increasing rapidly. Among older adults, pain is common and leads to greater acute care use. In jail, pain management is complicated by concerns about misuse and diversion. A lack of data about the prevalence and management of pain in older jail inmates limits our ability to develop optimal palliative care strategies for this population.

OBJECTIVE

To describe the prevalence of and factors associated with pain and analgesic use in a population of older jail inmates.

DESIGN

Cross-sectional study. χ(2) tests assessed association between characteristics, pain, and analgesic use.

SETTING/SUBJECTS

Two hundred ten jail inmates age 55 or older.

MEASUREMENTS

"Severe frequent pain" defined as "severe or very severe" pain experienced "frequently or constantly" using the validated Memorial Symptom Assessment Scale. Medical conditions, substance use, and analgesic treatment determined through self-report and jail medical records.

RESULTS

Participants' mean age was 59 years; 69% had multimorbidity; 75% reported any pain; 39% reported severe frequent pain. Report of severe frequent pain was associated with multimorbidity, functional impairment, and pre-jail acute care use (p<0.05), but not with substance use (57% versus 56%, p=0.89). Within a week of their interview, most participants with severe frequent pain had received an analgesic (87%) and many received an opioid (70%).

CONCLUSION

High rates of pain in a rapidly growing population of older jail inmates with multimorbidity and functional impairment suggest that jails are an important site for assessing symptom burden and developing appropriate palliative care interventions.

UNLABELLED

Article-at-a-Glance Background: Care transitions across health care settings are common and can result in adverse outcomes for older adults. Few studies have examined health care professionals' perspectives on important process measures or pay-for-performance (P4P) strategies related to transitional care. A study was conducted to characterize health care professionals' perspectives on (1) successful transitional care of older adults (age 65 years and older), (2) suggestions for improvement, and (3) P4P strategies related to transitional care.

METHODS

In a qualitative study, one-hour semistructured in-depth interviews were conducted in an acute care hospital, a skilled nursing facility, two community-based primary care practices, and one home health care agency with 20 health care professionals (18 physicians and 2 home health care administrators) with direct experience in care transitions of older adults and who were likely to be affected by P4P strategies.

RESULTS

Findings were organized into three thematic domains: (1) components and markers of effective transitional care, (2) difficulties in design and implementation of P4P strategies, and (3) health care professionals' concerns and unmet needs related to delivering optimal care during transitions. A conceptual framework was developed on the basis of the findings to guide design and implementation of P4P strategies for improving transitional care.

CONCLUSION

In characterizing health care professionals' perspectives, specific care processes to target, challenges to address in the design of P4P strategies, and unmet needs to consider regarding education and feedback for health care professionals were described. Future investigations could evaluate whether performance targets, educational interventions, and implementation strategies based on this conceptual framework improve quality of transitional care.

The aim of this study was to evaluate the effect of atorvastatin on lipid lowering, cardiovascular (CV) events, and adverse events in women compared with men in 6 clinical trials. In the Incremental Decrease in End Points Through Aggressive Lipid Lowering (IDEAL) trial (atorvastatin 80 mg vs simvastatin 20 to 40 mg), the Treating to New Targets (TNT) trial (atorvastatin 80 vs 10 mg), the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial (atorvastatin 80 mg vs placebo), and the Collaborative Atorvastatin Diabetes Study (CARDS), the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT), and the Atorvastatin Study for Prevention of Coronary Heart Disease Endpoints in Non-Insulin-Dependent Diabetes Mellitus (ASPEN) (atorvastatin 10 mg vs placebo), lipid changes on treatment were compared between genders with studies grouped by dose. The association of on-study low-density lipoprotein (LDL) cholesterol and CV events by gender was evaluated in the combined studies and the impact of gender on adverse events in each study separately. Major CV events occurred in 3,083 of 30,000 men (10.3%) and 823 of 9,173 women (9.0%). Changes in lipids were similar in women and men. Major CV events were associated with gender-specific quintiles of on-treatment LDL cholesterol for women and men. In women, LDL cholesterol was a significant predictor of stroke, but not in men. Discontinuation rates due to adverse events were higher in women in 4 of 6 trials, but in only 1 trial was a significant treatment-gender interaction seen. Myalgia rates were slightly higher in women in both statin and placebo groups. In conclusion, the response of women to atorvastatin was similar to that of men, with slightly more discontinuations due to adverse events. Higher on-treatment LDL cholesterol was significantly associated with more CV events in both genders, but the association was stronger for stroke in women and for coronary heart disease death in men.

OBJECTIVE

Trimethoprim-sulfamethoxazole prophylaxis is recommended for HIV-exposed infants until breastfeeding ends and HIV infection has been excluded. Extending prophylaxis with a focus on preventing malaria may be beneficial in high transmission areas. We investigated three regimens for the prevention of malaria in young HIV-exposed children.

DESIGN

An open-label, randomized controlled trial.

SETTING

Tororo, Uganda, a rural area with intense, year-round, malaria transmission.

PARTICIPANTS

Two hundred infants aged 4-5 months enrolled and 186 randomized after cessation of breastfeeding and confirmed to be HIV uninfected (median 10 months of age).

INTERVENTION

No chemoprevention, monthly sulfadoxine-pyrimethamine, daily trimethoprim-sulfamethoxazole or monthly dihydroartemisinin-piperaquine given from randomization to 24 months of age.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of malaria during the intervention period. Secondary outcomes included the incidence of hospitalization, diarrhoeal illness, or respiratory tract infection; prevalence of anaemia and asymptomatic parasitemia; measures of safety; and incidence of malaria over 1 year after the intervention was stopped.

RESULTS

During the intervention, the incidence of malaria in the no chemoprevention group was 6.28 episodes per person-year at risk. Protective efficacy was 69% [95% confidence interval (95% CI) 53-80, P < 0.001] for dihydroartemisinin-piperaquine, 49% (95% CI 23-66, P = 0.001) for trimethoprim-sulfamethoxazole and 9% for sulfadoxine-pyrimethamine (95% CI -35 to 38, P = 0.65). There were no significant differences in any secondary outcomes, with the exception of a lower prevalence of asymptomatic parasitemia in the dihydroartemisinin-piperaquine arm.

CONCLUSION

Monthly chemoprevention with dihydroartemisinin-piperaquine was well tolerated and associated with a significant reduction in malaria in young HIV-exposed children.